Traditional standards and specifications for concrete have largely been prescriptive, (or prescription-based), and can sometimes hinder innovation and in particular the use of more environmentally friendly concretes by requiring minimum cement contents and SCM replacement levels. In December 2004, the Canadian CSA A23.1-04 standard was issued which made provisions (a) for high-volume SCM concretes, (b) added new performance requirements for concrete, and (c) clearly outlined the requirements and responsibilities for use in performance-based concrete specifications. Also, in December 2003, the CSA A3000 Hydraulic Cement standard was revised. It (a) reclassified the types of cements based on performance requirements, with both Portland and blended cements meeting the same physical requirements, (b) allows the use of performance testing for assessing sulphate resistance of cementitious materials combinations, (c) includes an Annex D, which allows performance testing of new or non-traditional supplementary cementing materials. From a review of international concrete standards, it was found that one of the main concerns with performance specifications has been the lack of tests, or lack of confidence in existing tests, for judging all relevant performance concerns. Of currently used or available test methods for both fresh, hardened physical, and durability properties, it was found that although there may be no ideal testing solutions, there are a number of practical and useful tests available. Some of these were adopted in CSA A23.1-04, and it is likely that new performance tests will be added in future revisions. Other concerns with performance standards are the different perspectives on the point of testing for performance. Some concrete suppliers may prefer processes for both pre-qualifying the plant, and specific mixtures, followed only with testing only 'end-of-chute' fresh properties on-site. However, owners want to know the in-place performance of the concrete, especially with high-volume SCM concretes where placing and curing are important. Also, the contractor must be aware of, and share the responsibility for handling, constructability, curing, and scheduling issues that influence the in-place concrete properties.

A flat plate-column connection is susceptible to brittle punching shear failure, which may result in the necessity of shear reinforcement. In present study, experimental tests were performed to study the capacity of slab-column connections strengthened with lattice, stud rail, shear band and stirrup under gravity and cyclic lateral load. Among them, the capacity of the specimens with lattice are superior to the others due to the truss action of the lattice bars and dowel action of the longitudinal bars as well as the shear resistance of the web re-bar. On the other hand, the strengths of the specimens with stud rail, shear band and stirrup are lower than the estimated strength by the ACI, therefore design formulas of the ACI are needed to revise.

The purpose of this research is to study the seismic behavior of interior column-slab connections with different column aspect ratio, when subjected to combined gravity and cyclic lateral loading. The control specimen had square column, while the other specimens had rectangular column with aspect ratio of 0.5 and 2.0. From the test results, all of the specimens sustain lateral drifts as high as 4% with no more than a 20% decrease in peak lateral load capacity. And it appears that KBC Code(2005) procedure may be unconservative for connections with different column aspect ratio.

Accoarding as a specimen for reinforced concrete bridge deck was designed by each researcher's opinions, its size and shape was variable. Therefore, it makes difficult to comparison with other experiments. In the result of researching papers for design method of reinforced concrete bridge deck specimens, there is hardly found. The target of this study is introduction of the design method of a reinforced concrete bridge deck specimen. The most important point for the specimen design is materialization of the curvature of the real bridge deck. The result of this study appears that the specimens thickness effects highly to fit for the real reinforced concrete bridge deck's curvature.

Wheel load fatigue experiment is carried out on a FRP-concrete composite deck. In FRP-concrete composite deck, FRP plays a role of a main tensile member as well as a permanent formwork and concrete plays a role of a main compressive member. Wheel load fatigue experiment, which shows more realistic behavior than pulsating fatigue experiment, is selected as a fatigue performance evaluation method. Until 1,000,000 cycles of loadings, load resistant performance is maintained without any loss, while residual deflection is increased.

This study investigated headed bar anchorage of exterior beam column joints in nuclear power plants. In nuclear power plant structures, anchorage of headed bar is recommended to satisfy ACI 349-01 App. B that are based on the Concrete Capacity Design (CCD) method. However, CCD method may lead to very conservative results for beam column joints where head is anchored within the diagonal strut and concrete is confined by transverse rebar. Compared with results of 5 joint specimens, the anchorage capacities calculated by ACI 349-01 are underestimated by 70-90%. Therefore, it is necessary to amend ACI 349-01 for the mechanical anchorage in beam column joints.

In general, the shear behavior mode of URM wall expresses four types of modes such as rocking failure, sliding shear failure, toe crushing failure, and diagonal tension failure. From the comparison of each equation according to the shear behavior modes, the failure modes based on the aspect ratio and vertical axial stress can be expected. The objectives of this study is to find out the shear behavior of URM wall with different aspect ratio. The test results show that the aspect ratio is understood as an important variable.

An experimental investigation on the behavior of reinforced concrete coupling beams is presented. The test variables are the span-to-depth ratio, the ratio of flexural reinforcement and the ratio of shear rebar. The distribution of arch action and truss action which compose the mechanism of shear resistance is discussed. This study proposes the deformation model for reinforced concrete coupling beams considering the bond slip of flexural reinforcement. The yielding of flexural reinforcements determines yielding states and the ultimate states of reinforced concrete coupling beam are defined as the ultimate compressive strain of struts and the degradation of compressive strength due to principal tensile strain of struts. It is expected that this model can be applied to displacement-based design methods.

The purpose of this study is to estimate the shear strength of high-strength SFRC beam by the comparison of normal-strength SFRC beam. To achieve the goal of this study, 9th specimens were made and tested. From the analyzing test result and previous researches, the shear strengthening effect of steel fiber in high-strength is evaluated as superior than normal-strength concrete. And the proposed shear strength equation of SFRC is underestimated the shear capacity of high-strength SFRC beam. Finally, the shear strengthening effect of steel fiber in high-strength concrete is evaluated about 3.5 times larger than normal-strength concrete.

The effect of the steel ratio on the behavior of continuously reinforced concrete pavement (CRCP) under moving wheel loads and environmental loads were investigated in this study. The CRCP sections having different steel ratios of 0.6, 0.7, and 0.8% were considered: (1) to evaluate the load transfer efficiency (LTE) at transverse cracks; (2) to investigate strains in CRCP when the system is subjected to moving vehicle loads; (3) and to investigate the time histories of the crack spacing variations. The LTEs were obtained by conducting the falling weight deflectometer (FWD) tests. The strains in the concrete slab and the bond braker layer under moving vehicle loads were obtained using embedded strain gages. The results of this study show that the LTEs at transverse cracks are very high and not affected by the steel ratio. The strains in CRCP under vehicle loads become smaller as the vehicle speed increases or as the wandering distance increases; however, the strains are not clearly affected by the steel ratio. However, the changes in the crack spacings are affected by the steel ratio.

This study investigated the behavior of R/C column confined with headed crossties subjected to eccentric loading. The 16 specimens are designed to have adequate confinement steel, determined by ACI seismic design. The variables studied in this research test are eccentricity to depth ratios, spacing of lateral steel and the anchor type of end of crossties. From the test results, all columns showed similar behavior up to the peak load but those columns laterally confined with head presented more ductile behavior after the peak load. The comparisons indicate that the flexural behavior of confined-concrete columns can be computed resonable accurately by P-M interaction curve.

Three reinforced concrete rigid frames and infilled rigid frames with new retrofitting system were tested under both vertical and cyclic loadings, Experimental programs were carried out to evaluate and improve the seismic performance of such test specimens, such as the hysteretic behavior, the maximum horizontal strength, crack propagation, and ductility etc. under load reversals. All the specimens were modeled in one-third scale size. For specimens(RFHPC, RFAR) designed by the improving of seismic performance of the rigid frame using the high ductile fiber composite PC panel and ALC panel system, load-carrying capacities were increased $1.45{\sim}2.28$ times, and hysteretic behavior was very stable during the final tests in comparison with the standard specimen(SRF).

Recently, several researches have been performed on the prediction of vertical vibration on structures by using an analytical method. However, these studies have been focused on mainly the vibration analysis through analytical modeling of structures. This study aims to investigate the characteristics of vertical vibration transfer in terms of the directions of transfer(upward transfer and downward transfer) on the shear wall building structures due to heel-drop impact forces. In order to examine the characteristics of vertical vibration transfer, the mode analysis and the impact experiment were conducted several times on two shear wall building structures. The results of this study suggest that the characteristics of vertical vibration transfer are similar in terms of the directions of transfer.

The purpose of this study is to investigate the relation between color change and residual compressive strength in concrete exposed to high temperature. In order to study the color image analysis, the specimens have been tested with variables of concrete strengths(20Mpa, 40Mpa, 60Mpa) in transient heating conditions($800^{\circ}C$ heating and 2 hour preservation). The results show that the residual strength of specimens are coincident with the full development of the pink/red color and the method may be used to define the distance from a heated surface where strength degradation has occurred.

In the current study, a force-based fiber frame finite element model of FRP concrete structural members has been developed. For compressive behaviors of confined concrete wrapped by FRP jackets, the multiaxial behavior of concrete has been considered with the equivalent tangent modulus of concrete. The behavior of FRP jackets has been modeled using the mechanics of orthotropic laminated composite materials in two-dimensional stress states. The force-based finite element formulation is based on the force-interpolation functions within the element without using the displacement shape functions to satisfy the equilibrium in element levels.

In this study, the fatigue tests were performed on a series of reinforce concrete beams with type of aggregate to investigate the fatigue behavior. The four point loading system is used in the fatigue tests. In these tests, relations between the repeated loading cycles and mid-span deflections, number of repeated loading cycles when specimen was fractured were observed. On this basis, the mid-span deflections, the crack growth and failure mode of beams were studied. The result of tests, reinforce concrete beams with recycled aggregate were about similar failure mode with natural aggregate concrete beam.

The flexural performance of FRP-concrete composite deck in the connection between decks is evaluated. FRP-concrete composite deck, an innovative system is composed of concrete in the top and FRP panel in the bottom. The experiments are carried out on specimens with different details, such as FRP module and reinforcement of FRP re-bars. As a result, we verify that the transverse connections between our FRP-concrete composite decks with presented details secure enough safety and serviceability.

Buried pipeline is a indispensable factor of leading smoothly a society as a primary role. Recently, as a matter of convenience of construction and the economical purpose, the use of Precast Concrete products quickly increased. But there was various damage forms in a part of joint of Precast Concrete buried pipeline. The purpose of this study is to propose the new type of the flexible rubber packing material (EF) which could resist a permanent deformation of the ground or an earthquake and to investigate its safety together with effectiveness as conducting experiment and analysis.

This paper reports fatigue test results of 1/3 scaled PSC slab models using moving wheel loading machine. The purpose of the test is to improve the fatigue formulas by comparing the existing formulas with the test results. Based on the result, improved fatigue formula is proposed for the PSC slab.

As an alternative of conventional prestressed concrete (PSC) girders, various types of PSC girders are being developed and applied in bridge structures. Incrementally prestressed concrete girder is one of these newly developed girders. According to design concept, these new types of PSC girders have considerable advantages to reduce their self-weight and make spans longer. However, dynamic interaction between bridge superstructures and passing trains would be sometimes one of critical issues in these more flexible railway bridges. Therefore, it is very important to evaluate modal parameters of newly designed bridges before conducting dynamic analyses. In the present paper, a 25 meters long full scale PSC girder was fabricated as a test specimen and modal testing was carried out to evaluate modal parameters including natural frequencies and modal damping ratios at every prestressing stage. In the modal testing, a digitally controlled vibration exciter as well as an impact hammer is applied to obtain frequency response functions more exactly and the modal parameters are evaluated varying with construction stages. Prestressed force effects on changes of modal parameters are analyzed at every incremental prestressing stage.

Nowadays, increase of demands on efficient utilization of resources while construction process stimulates structural engineers to select remodeling to improve old buildings. To analyze the effects of openings that may be installed in the course of remodeling old buildings, an experimental research was carried out using four approximately half scale of specimens subjected to constant axial forces, and cyclic loading to simulate seismic conditions. Consequently, the existence of opening was verified to induce different observed damages, which caused by reduction of compression strut support formed on the surface of wall. Especially, the maximum force was revealed to decrease approximately 35% as openings were existed. As this tendency was appeared with stiffness and energy dissipation capacity.

It has been shown that many reinforced concrete(RC) structures designed without seismic details have experienced brittle shear failures in the beam-column joint area and may result in large permanent deformations and structural collapse. In this study, experimental investigations for RC beam-column joints strengthened with the carbon fiber-reinforced polymer(CFRP) under cyclic loadings were presented. The use of CFRP in the joint was varied to determine the effective way of improving the structural performances of RC joints. Ten RC beam-column joints were designed and tested with cyclic loadings. The experimental results showed that the use of CFRP in RC joints would be very effective solutions to improve the seismic performances of the non-seismic RC joints. All of the non-seismic design specimens strengthened with CFRP sheets showed the significant increase of strength and ductility.

As various loads are applied to a reinforced concrete beam, cracks may occur by the influence of shear and bending moments. These cracks propagate as the applied loads are increased. In addition, the deflection of the reinforced beam is also increased at the same time. Even though it is commonly accepted that the cracking and the deflection of a reinforced concrete beam are very closely related, many studies have not been conducted to provide basic data and to develop the relationship between them. In this study total seventeen specimens subjected to bending were tested with different concrete strength, coverage, amount of steel and de-bonding bars. The effects of these parameters on the relationship between cracking and deflection were carefully checked and analyzed.

Concrete beams reinforced with fiber reinforced polymer (FRP) bars exhibit large deflection and crack width as compared to concrete beams reinforced steel due to modulus of elasticity of FRP bars. Current design code for prediction and crack width developed in concrete structures reinforced with steel bars may not be used for concrete beams reinforced with FRP bars. Thus a number of researcher have attempted to propose modifications to the ACI 318 empirical equation for estimating the effective moment of inertia of reinforced concrete beams. Others used numerical method to calculate the deflection. The purpose of this paper is to evaluation of methods of ACI 440.1 R-01, ISIS Canada design manual, and others for predicting deflection for glass fiber reinforced polymer reinforced concrete beams.

The research reported here is concerned with the effects of the fiber combination condition and water/cement ratio on the mechanical properties of high performance fiber-reinforced cementitious composites(HPFRCC). An experimental investigation of the behavior of steel cords(SC) and SC and Polyethylene(PE) hybrid fiber reinforced cementitious material under compressive and tensile loading is presented. In this experimental research, the tensile and compressive strength and strain capacity of HPFRCC were selected using the cylindrical specimens. The results show that W/C ratio is a significant effect factor on the compressive and tensile performance of HPFRCC. The envelope curve concept applies to hybrid fiber-reinforced cementitious composites in tension just as it does to compressive stress-strain curve of fiber-reinforced cement composites. For practical purposes, the tensile envelope curve may be taken to be the same as the monotonic tensile stress-strain curve.

This paper presents the comparison of the bond behavior of various FRP rebars. A total of 9 specimens including steel reinforcement were tested through direct pull-out test procedure. The test results have revealed that the bond behavior was affected by the deformation shapes and surface treatments. The newly proposed FRP rebar by KICT showed good bond strength and ductile behavior after failure.

A bending moment $M_u$ transferred at slab-column connection is resisted at the slab critical section by flexure and shear. The ACI 318-05 Building Code(1) gives an empirical equation for the fraction ${\gamma}_{\upsilon}$ of the moment $M_u$ to be transferred by shear at the slab critical section at d/2 from the column face and also the effective wide(c+3h). The equation is based on tests of interior slab-column connections without shear reinforcement. In order to investigate the data eight test specimens were examined. The test shows that increased slab load substantially reduces both the unbalanced moment capacity and the lateral drift capacity of the connection. Especially, the specimens with the bottom reinforcement existence and nonexistence, appears remarkable differences. Studies also show that the code equation for ${\gamma}_{\upsilon}$ does not apply to all cases. The purpose of this study is to compare the test results with present ACI 318-05 Building Code provisions for design of slab-column connections and with the analysis of the experimental data for a new limitation of strength equation without shear reinforcement and bottom reinforcement.

Owing to Higher story tendency and ceiling hight restriction of recent times, even though the depth of Coupling Beam decreases the demand efficiency is coming to be high rather so it is the difficult to satisfy a demand efficiency with the actual existing RC/Steel condition. It has been researched a lot of methods as an alternative plan about these but designer cannot apply them for the reason ; the structure standard and theory background are not taking a triangular position. As accomplishing the test research about the beams-wall connections department of steel-plate composite coupling beams from the research in the study it examines closely the beams-wall connections conduct quality and tries to provide the fundamental data for reasonable and optimum connection department designs. It knows that connection fixation degree and composite conduct degree of member part together become the important variable showing an energy dissipation ability in Test result.

In this paper, performance verification of connection between bridge rail and FRP decks are performed by static test. Also, the effect of flexible bridge rail failure to behavior of FRP deck are examined. Commercial products of flexible bridge rail are applied to test specimen, and 6 types of FRP deck-to-bridge rail connection system are considered. By the test results, 6 types of connection system by the connection method have similar structural capacity and have enough safety margin. Therefore, it is determined that 6 kinds of bridge rail considered in this study can be applied to bridge effectively by the cases of bridge field condition.

Shear wall-frame system is one of the most, if not the most, popular system for resisting lateral loads. The core is the primary lateral load-resisting systems, the perimeter frame is designed for gravity loads, and the connection between perimeter frame and core is generally a shear connection. Specially, single plate shear connection have gained considerable popularity in recent years due to their ease of fabrication and erection. Single plate shear connection should be designed to satisfy the dual criteria of shear strength and rotational ductility. An experimental program was undertaken to evaluate seismic behavior of single plate shear connection. The main test variable is the reinforcing detail of connection. Through the experimental program, the cyclic behavior of typical and reinforcing single plate shear connection was established.

A method of plane expansion of reinforced concrete apartments using precast concrete was developed. The method increased the stiffness of the precast slab using two ribs and allowed to cast concrete for multi stories. The proposed precast system is capable to construct concrete slabs without props. Ten reinforced concrete slabs were tested in order to investigate the stiffness increase of the developed precast slab with two rids. Comparison between the proposed precast slab and the slab without ribs indicated that the deflection of the precast slab was decreased by using rids.

In many previous studies, a prestressed concrete column has a larger flexural strength, shear strength and restoring force than a RC column. Recently, a precast prestressed concrete column is rising up a very rational column structure in that a economic aspect. In a precast prestressed concrete column, it makes in a factory. So, it needs a small construction site and acquires a higher durability than a cast in place concrete column. Seven precast concrete columns were tested under a constant axial load and a cyclically reversed horizontal load to investigate the performance. It is designed with a hollow section and consisted of 4 segments. The main variables of the test were a amount of prestressed, a type of joints and a boding type of strands. The test results show that the performance of a precast prestressed concrete column; failure mode, maximum load, energy dissipation and stiffness degradation.

The purpose of this research is focused on evaluating the flexural behavior of reinforced concrete beam having 22mm diameter re-bars by lapping methods. To compare the existent lapping method with mechanical lapping methods, four cases of concrete beams were tested to be failed flexurally by monotonic loading. Based on test results, the relations between load and displacement, ductility, maximum load was comparatively analyzed. The structural performance on four cases of members were evaluated.

An experimental study was conducted to study the behavior of slab-column connections under lateral load. Test variables include gravity shear ratio$(V_g/V_o=0.3,\;0.5)$ and flexural reinforcement ratio of slab(p=0.01, 0.015). Strength and ductility of tested specimens were evaluated in accordance with gravity shear ratios and slab reinforcement ratios. Shear stresses of Code's equation at the critical section were also compared with experimental results.

The numerical analysis and the experiment was performed to investigate the influences of shear connector on shear resistance capability. The numerical analysis's results should that the H/B ratio of shear key is more effective than angle of shear key against shear strength and shear behavior, and it is more desirable to use a half of the H/B ratio of shear key. The specimen was made with same condition as AASHTO recommended. There model tests were performed under various form of shear key, number, arrangement reinforcement and condition using epoxy. As a result of the experiment, there is little difference(or there is no difference) between the case of using epoxy on shear connector and the unused case.

I-section prestressed concrete(I-PC) beam crack due to low tensile strength, may decrease rigidity and structural performance by excessive deflection. In an effort to this problem, in this research, I-section prestressed dual concrete(I-PDC) beam has been proposed, consisting of normal strength concrete in compression zone, and high performance steel fiber reinforced concrete(HPSFRC) with a bottom flange depth in tensile zone. Crack formation and its propagation are controlled by the HPSFRC in I-PDC beam. The initial cracking and service limit loads are increased along with the load carrying capacity and flexural stiffness.

A new bridge system described in this paper uses concrete-filled steel tube (CFT) girders as a replacement for conventional girders. Experimental investigations were carried out to comprehend the flexural behavior of CFT girder-slab deck composite section. The experimental investigation consisted of designing and constructing a test specimen and loading it to collapse in bending to check the applicability of the system. The test results showed that concrete filled steel tube girders have good ductility and maintain its strength up to the end of the loading. In the test, the flexural behavior of each specimen of CFT girder-deck composite section is identified.

The purpose of this study is to investigate the effect of post-fire-curing on the strength recovery of fire-damaged concrete The 170 specimens have been tested with variables of concrete strengths(20, 30, 40, 50, 60Mpa) exposed to elevated temperatures till $600^{\circ}C$ and $800^{\circ}C$. After natural cooling, the specimens were subjected to post-fire-curing in water and in a controlled chamber for a total duration of 56days. Unstressed compressive strength was conducted to examine the change in the concrete. The test results indicated that the post-fire-curing results in substantial strength recovery and its extent depend on the method and duration of recuring.

To restore an earthquake damaged community as quickly as possible, well-prepared reconstruction strategy is most essential. This paper reports experimental data on the seismic capacity of diagonal reinforced HPFRCC coupling beams with the Japanese Standard for Seismic Evaluation of Existing RC Buildings. Precast Based on the experimental results, HPFRCC specimen have more residual seismic capacity than RC specimen, but much study is necessary to improve the accuracy of the damage evaluation.

The purpose of this study is to investigate the inelastic behavior of precast segmental prestressed concrete bridge piers. A computer program, named RCAHEST (Reinforced Concrete Analysis in Higher Evaluation System Technology), for the analysis of reinforced concrete structures was used. Material nonlinearity is taken into account by comprising tensile, compressive and shear models of cracked concrete and a model of reinforcing steel. An unbonded tendon element based on the finite element method, that can represent the interaction between tendon and concrete of prestressed concrete member, is used. A joint element is newly developed to predict the inelastic behaviors of segmental joints. The proposed numerical method for the inelastic behavior of precast segmental prestressed concrete bridge piers is verified by comparison with reliable experimental results.

The objective of this study is to evaluate residual seismic capacity of Unreinforced Masonry(URM) walls which were damaged by earthquake through the measurement of frequency. Three URM walls which made the shape ratio(1/h, 1.0, 1.5, 2.0)to be a variable were tested for the objective. It was seen that the natural frequency decreased with growing at rotation angle. Also, this study found out that residual seismic capacity and natural frequency of URM walls is correlative.

Since the columns with flexure-shear failure have lower ductility than those with flexural failure, shear capacity curve models shall be applied as well as flexural capacity curve in order to determine ultimate displacement for seismic design or performance evaluation. In this paper, a proposed modified shear capacity curve model is compared with the other models such as the CALTRANS model, Aschheim et al.'s model, and Priestley et al.'s model. Four shear capacity curve models are applied to the 4 full scale and 7 small scale circular bridge column test results and the accuracy of each model is discussed. It may not be fully adequate to drive a final decision from the application to the limited number of test results, however the proposed model provides the better prediction of failure mode and ultimate displacement than the other models for the selected column test results.

The definition of the Dual system is that the total seismic force resistance is to be provided by the combination of the moment frame and the shear walls or braced frames in proportion to their stiffness and the moment frame shall be capable of resisting at least 25% of the design force in Korean Building Code 2005 (KBC 2005). But, the definition of moment frame is ambiguous whether the moment frame include the imaginary columns in the shear wall (Case I) or include only the columns outside the shear wall (Case II). 60-story RC building was designed as dual system for Case I and Case II, and the required strength and reinforcement are compared. Moment and axial capacity of the shear wall of Case II decreased about 5% due to the absence of the column in the shear wall. The requirement of upper and bottom reinforcement of slab in Case II increased 13% and 40%, respectively, when compared to those of Case I. The required longitudinal reinforcement in columns for Case II is about 1.5 times larger than that of Case I.

This study represents results of fragility curve development for 4-span continuous bridge. 2 type bridge model is chosen frame type and 2-roller 1-hinge type. To research the response of bridge under earthquake excitation, Monte Carlo simulation is performed to study nonlinear dynamic analysis. For nonlinear time history analysis a set of 150 synthetic time histories were generated. Fragility curves in this study are represented by lognormal distribution functions with two parameters and developed as a function of PGA. Five damage states were defined to express the condition of damage based on the actual experimental damage data of bridge column. As a result of this research, the value of damage probability corresponding to each damage state were determined and frame type bridge are favorable under seismic event.

In order to evaluate the seismic performance of reinforced concrete bridge piers, an inelastic time-dependent element is proposed. The proposed element enables increased characteristics due to structural intervention (i.e., repair and retrofitting) to be accurately reflected to the degraded strength and stiffness of the members. Comparative studies are conducted for reinforced concrete bridge columns being repaired and retrofitted and show good correlation between analytical prediction and experimental results. In addition, a nonlinear time-history analysis of a reinforced concrete bridge under multiple earthquakes confirms the applicability and effectiveness of the present development.

Three reinforced concrete shear wall and infilled shear wall using retrofitting system were constructed and tested under both vertical and cyclic loadings, Experimental programs were carried out to evaluate and improve the seismic performance of such test specimens, such as the hysteretic behavior, the maximum horizontal strength, crack propagation, and ductility etc. under load reversals. All the specimens were modeled in one-third scale size. For specimens(RWAHC, RWXHC) designed by the improving of seismic performance using the high ductile fiber composite mortar, anchoring, and advanced detailing system for the reinforced concrete shear wall load-carrying capacities were increased $1.1{\sim}1.22$ times in comparison with the standard specimen(SRW).

This study presents the performance evaluation of a tuned mass damper (TMD) for controlling seismic responses of the nonlinear hysteretic structure represented by a Bouc-Wen model, considering that the general reinforce concrete building structures subject to earthquake load show nonlinear hysteretic behavior. Numerical analysis result indicates that the performance of a passive TMD of which design parameters are optimized for a elastic structure deteriorates when the hysteretic portion of the structural responses increases, while a semi-actively operated TMD shows about 15-40% more response reduction than the TMD.

The objectives of this study is to find out the relationship of crack width and residual seismic capacity of Unreinforced Masonry(URM) walls which were damaged by earthquake. Three URM walls which made the shape ratio(1/h, 1.0, 1.5, 2.0)to be a variable were tested for the objective. It was seen that the crack width increased with growing at rotation angle. Also, this study found out that failure mode affects crack type of URM. In other words, horizontal and vertical crack was increased in rocking and sliding failure mode respectively.

It is well known that RC piers having 50% of lap-spliced longitudinal bars in plastic hinge region have a good ductility relatively. But the deformability under various loading condition is not confirmed. In this study scale models with different confinement were tested under different axial loads and loading cycles. It was confirmed that deformability was decreased with increase of axial force and number of loading cycles and that the models having 75% of confinement specified in present code satisfy the required seismic performance.

The past Korean Bridge Design Specifications have no limitation on the amount of lap splices of longitudinal bars in the plastic hinge zone of piers. A majority of bridge piers which have been non-seismically designed might have some lap splices in plastic hinge zone. Also a number of those piers in Korea have a low aspect ratio(height/section area). So, some problems such as low ductility behavior may happen. In this study, the real pier which was non-seismically designed and has a low aspect ratio was selected for the quasi-static tests. Two groups of full scaled RC pier models of which aspect ratios are about 2.26 and about 2.67 were fabricated. And then, quasi-static tests according to the drift level history method were implemented. From the test results, the failure of these test specimens have been shown in the complex shear-flexural or shear modes. The low aspect ratio and the lap splice have largely influenced on the seismic performance of bridge piers.

Pull-off test is widely used to evaluate bond performance between concrete and FRP composite. However, reliability of experiment result declines due to many difference between test methods of each national standards. This study analyzed problems of various existing test methods for pull-off test and suggested standardized test method. In addition, since tensile strength of concrete is smaller than bond strength of epoxy resin, maximum bond strength of epoxy resin shall be limited within tensile strength of concrete. Alternative testing method, therefore, which decrease FRP adhesion areas than concrete adhesion areas is suggested to widen test range of bond strength in pull-off test. In the experimental results, bond performance can be estimated up to two times of tensile strength of concrete by reducing FRP adhesion areas by 1/3.

Strengthening with externally post-tensioned CFRP strips is more effective in increasing load carrying capacity of existing structures as well as reducing crack width and deflection. This study developed concrete embedded anchorages system for externally post-tensioned CFRP strips, and carried out experimental study to verify anchoring performance quantitatively. Through experimental results, anchoring strength of concrete embedded anchorage were quantified into shear strength of anchor bolt, bearing strength of concrete at the front of anchor plate and bond strength between anchor plate and concrete surface. In addition, overall anchoring performances according to combination of each unit force are examined in this study.

Conventionally, it used to be focused on simply prevention of further settlement of structures, where, much of problems were raised and sometimes the construction itself was not possible. Further, rough estimation of the ground, which is unseen, often incurred many troubles in the maintenance. D-ROG method is a high-tech technology that changes almost all of the concepts on the conventional grouting, is expanding its application scope spanning from the restoration of settled structures to ground strengthening works necessary for building enlargement and remodeling.

A series of three shear wall specimens was tested under constant axial stress and reversed cyclic lateral loading in order to evaluate the seismic retrofit that had been proposed for the shear wall with the opening induced by remodeling. One of these specimens was tested in the as-built condition and the other two were retrofitted prior to testing. The retrofit involved the use of carbon fiber sheets and steel plates (thickness of 3mm) over the entire face of the wall. The test results show that the ultimate failure modes of the specimens were found to be shear fracture of the wall around the opening and two difference types of retrofitting strategy make the different effects of a rise in the strength of each specimen.

The needs for strengthening and rehabilitation of the concrete bridges are a growing concern in many countries and has been emphasized in various researches and papers. Traditional external post-tensioning method using either steel bars or tendons is commonly used as a strengthening method. However, the method has some disadvantages such as stress concentration at the anchorages. Multi-stepwise thermal prestressing method is a newly proposed method for strengthening and rehabilitation of concrete girder bridges. Founded on a simple concept of thermal expansion and contraction of steel, the method is a hybrid method of external post-tensioning and steel plate bonding, combining the merits of two methods. In this paper, basic concepts on strengthening and rehabilitation of concrete girder are presented and an illustrative experiment is introduced.

In this research, a precast concrete slab with two ribs was developed to increase the stiffness of slab. The developed precast slabs are allowed to cast concrete for multi stories and to construct concrete slabs without any props. Seven concrete slabs were tested to investigate the behavior of the developed precast slabs. Test results indicated that the developed slabs showed a similar behavior with the slabs without ribs.

This paper presents experimental studies on investigating the seismic retrofit performance of reinforced concrete rectangular columns with poor lap-splice details using GFRP wrapping. Six columns have been tested. The GFRP retrofitted columns with same 7.5 mm thickness have two section shapes, i.e., rectangular and elliptical sections. The GFRP height was changed from 450 mm to 900 mm. The performance of GFRP retrofitted columns which have different shapes and height are verified.

This paper presents experimental studies on investigating the seismic retrofit performance of reinforced concrete circular columns with poor lap-splice details using GFRP wrapping. Four 1/2 scale-down model columns have been tested. The as-built column is expected to suffer brittle failure due to the bond failure of lap-spliced longitudinal reinforcement. The retrofitted columns using GFRP wrapping showed significant improvement of seismic performance.

Five bench scale specimens were used to evaluate corrosion performance of damaged epoxy-coated bars in chloride contaminated concrete. The test specimens were subjected 48 weekly cycles of ponding with sodium chloride solution and drying. Test results using linear polarization technique show that the current density of specimen with conventional steel becomes $0.715\;{\mu}A/cm^2$ indicating that the steel bars are in moderate or high corrosion condition. However, the corrosion rates of the specimens with damaged epoxy coated bars are much below $0.1\;{\mu}A/cm^2$ and the bars appears to be in passive condition. The corrosion protection performance provided by calcium nitrite is better than that of specimens with the other two inhibitors.

This study investigates the flexural behavior and strengthening performance of RC beams with unbonded prestressing CFRP laminates through static bending tests. The aluminum anchorage system has been developed in tins study and successfully applied to the test specimens. The prestressing level of CFRP laminatehas was 0 %, 20 %, 30% and 50 % of its tensile strength. Experimental results revealed that RC beams with unbonded prestressing CFRP laminates showed increased crack load and yield load according to the level of prestress. It has also been observed that the length of the CFRP laminates does not have significant effect on the maximum load.

This paper presents results on static and cyclic loading tests of anchorage system for externally prestressed CFRP plate. A total of 6 specimens have been tested. The specimens can be classified into the concrete surface specimens and the concrete near surface mounted specimens. Static test results before and after cyclic loading test reveal that anchorage system for externally prestressed CFRP plate has static capacity more than CFRP tensile strength.

External pre-stressing strengthening method is the most popular way to strengthen concrete structures because of its efficiency and economic advantage. The laboratory test was performed to reinforce the slave bridge with the external tendon strengthening by longitudinally and transversally, which is concerned with formal feature of slave bridge, generally. Based on this test, anchoring device to strengthen the external tendon strengthening method was established and its strengthening effects were verified by evaluating the load bearing capacity.

Bond between reinforcing bar and the surrounding concrete is made up of three components. There are chemical adesion, friction, and mechanical interaction between the rib of the bar and the surrounding concrete. bond of deformed bars depends primarily on the beraing of rib deformation anainst the surrounding concrete. The final objective of the study is to enhance structural stability, and workability thorough increasing the bond strength between deformed bar and surrounding concrete. The results of this study will be used to shorten bond and development length by $20{\sim}30$ percent and it will facilitate to use of high strength and high-relative rib area bars.

There are many structures attacked by chloride ions near a marine environment. And they are attacked by a salt of de-icing chemicals. So, the embedded reinforcement is corroded. In the same time, these are under a fatigue loading by a traffic loading in bridges. In previous studies, there are many researches that deal with a bond behavior under a monotonic loading according to the rate of a steel corrosion. But there are most cases that the steel corrosion and the repeated loading are acted on structures simultaneously. So, in this study, it is investigated a fatigue-bond behavior of RC structures under a steel corrosion and a fatigue loading. Main variables of the test are a corrosion of steel reinforcement and a level of stress.

The aims of this study are to investigate rib geometries of reinforcing bars commercially available in Korea, Japan and USA, and evaluate bond performance using beam-end test specimens. Measurement of rib geometries of the bars include nominal area, average distance of rib, height of rib and an angle of rib perpendicular to bar axis. The result of this study show that rib height of Korean reinforcement bars are much less than those of Japan and USA resulting in the lowest value of relative rib area. Average bond strength of Korean D25 deformed bars is known as 9 % less than that of bars produced in USA. Bond strength depends primarily on the relative rib area. Bond strength of the high relative rib area bars produced in USA show 18% higher than that of bars produced in Korea.

This study is to examine bond strength of beam reinforced with GFRP rebar under 4-point bending test by adopting BRITISH STANDARD. The variables were made to have bonding length of 5times$(5d_b)$, 10times$(10d_b)$ and 15times$(15d_b)$ of the nominal diameter of GFRP rebar and were done to analyze the relationship between the bonding strength and the slip. In the result of the test, pull-out failure was dominant in the $5d_b$ and $10d_b$ specimen, both patterns of the pull-out failure and concrete splitting failure appeared in the $10d_b$. On the other hand, the $15d_b$ specimen showed only concrete splitting failure at the end of bonding length. Therefore, it was prove that available bonding length of the GFRP rebar under bending condition on static test is over $15d_b$ then farther research such as fatigue bending test, development of bonding model, FEM parameter study should be performed.

Headed bars have used to the anchoring of the tension or compression longitudinal bars and of the shear reinforcing bars. Recently, lap splices of headed bars are attempted to the joints of precast concrete members and to the connections between old and new concrete members. Previous Michael's experimental research showed that confinement details had an effect on the lap splice performances of headed bars. In this study, the lap splice performances of headed bars(D25) with lap length and confinement details are evaluated through the experimental works. Four specimens, of which variables were the lap length of headed bar and the type of confine details, were tested for the performance evaluation on lap splice. Test results show that the lap length confinement reinforcement improve the performance of lap splice.

Glass fiber reinforced polymer (GFRP) bars gain increasingly more attention in the civil engineering community. GFRP reinforcement for concrete does not have the same shape as steel reinforcement. Therefore, the bond performance of FRP bars, unlike that of steel, is dependent on their design, manufacture and mechanical properties. It was tested in order to examine the bond behavior of GFRP bars under different compressive strength of concrete. Test results showed that the bond strength of GFRP increased with the compressive strength of concrete.

The purpose of this study is to introduce design practice for prestressed concrete box girder with AASHTO LRFD Design Specification. Distinctive features of viaduct girder of Incheon Bridge are pre-tensioned transverse tendon, 3-dim. transverse analysis, enlarged opening in diaphragm and so on.

The HIBRAND located in Yangjaedong, Seochogu, Seoul is a large complex shopping center of total space 48,000 p'yongs which consists of a nineteen-story business facility and a six-story sale facility. In the case of a big construction work in the downtown, they are suffered much difficulty by construction period and working space lack. They, however, can satisfy construction period, constructability and quality using a PC system in HIBRAND. Also, we maximized the advantage of each material being the abreast of a RC and steel structure method partially and devised a reasonable copula. A PC system with advantages of construction period, constructability and quality assurance should be actively practiced to big downtown construction work.

The temperature difference of deck and girder is one of the major factors that affect the stress distribution of a section, and therefore, the design of a composite girder bridge. However, domestic design codes of highway and railway bridges, respectively, present different shapes of design equations regarding the temperature difference, which may induce some confusion to the designers. In this study, each design equation is investigated on a theoretical basis and compared together. Some other methodologies such as finite element method and other equations from a different point of view are also taken into account for further comparison. An example of a railway bridge is presented to verify the result of each scheme.

The fully embedded composite truss beam is developed based on composite member, truss system before composite and beam system after composite. The proper design concept and method of the fully embedded composite truss beam are discussed. A bending test on the fully embedded composite truss beam with span length 25.0m is carried out to investigate the flexural behavior and ultimate strength of the developed structure up to failure. A good agreement between the measured and predicted results are observed.

The purpose of this study is to develop Performance Based Design Method based on application of Fragility Method. Fragility Method has been used in predicting failure of structure due to seismic action, However, development of Fragility Curve based on material or construction for PBD is developed, This paper suggests that Fragility Method can be modified for PBD and can assess the performance of concrete material or construction.

In the present study, design methodologies for effective width of slabs in slab-column connections were evaluated in comparison with the experimental results on the full-scale slab-column connections. The design methodologies are as follows: the methodology proposed by Jacob S. Grossman and the methodology proposed by Choi & Song. The former does not predict the stiffness change of the slab-column connection due to the change in the column section shape and the latter overestimates the stiffness when edge length of the column section in the loading direction is long. Accordingly, the equation to calculate the effective width of slabs should be modified to reflect the effect of the change in the column section shape.

The objective of this study is to evaluate the optimum thickness of High Performance Concrete bridge deck pavement. The application of High Performance Concrete bridge deck pavement with micro-silica was introduced to north America in the early 1980's. In order to decide the optimum thickness of High Performance Concrete bridge deck pavement, we conducted Finite Element Method analysis with Incheon Grand Bridge constructed by SAMSUNG E&C. From the FEM results, a thickness of five centimeters of High Performance Concrete bridge deck pavement with micro-silica is considered as a resonable value compared with the conventional asphalt bridge deck pavement.

This study was conducted to develop the crack location technique for CFRP reinforced concrete beam using AE method. To experimentally prove the crack source location made of four reinforced concrete beams strengthened in shear with CFRP. The results compared the real cracking location with the source location has perceived by AE monitoring, before it is appeared the primary crack by visual observation. So, This study used by a basic data in constructing the system of the failure warning at application.

Strengthening method using CFS have been developed for the rehabilitation of structures. However, it is very difficult to estimate their resistance capacity after retrofit. Therefore, damage information for strengthened structure with CFS investigated and the estimation method structural capacity by using the damage information is developed. The final objective of this research work is to propose the guideline and method for resistance capacity estimate of structure. In this paper, experimental study result with test parameters of number of carbon fiber sheets and bonding ratio is introduced.

In this paper experimental tests were performed to evaluate velocities of the acoustic waves through prestressed concrete beam and source locations using AE technique. Seven AE sensors are mounted on the surface of 5m length test beam with equal spacing and using Schmidt Hammer AE events are made 18 locations. The velocities of AE signals are evaluated using the time differences of arrival times and the distances between the AE source loactions and the AE sensor locations. In addition, using the Least Square Method, the AE source locations are re-evaluated reversely using both of the arrival times and the velocities of AE signals. Test results show the average velocity of the AE signals is about 4,000m/sec and the velocity decreased with the increase of the trevalling times due to the effect of attenuation. Based on the estimation of the source locations, it is observed that the accuracy of source location is increased when the velocity of each AE sensor used rather than the average velocity.

Generally, fragility curve has been used in predicting failure of structures due to seismic actions. In this research, the method of drawing fragility curve has been applied to evaluating success/failure of structures and satisfactory/unsatisfactory of concrete mixture performance based on material parameters. In the paper, a detailed explanation of the procedure of drawing fragility curve based on material parameter has been introduced. Fragility curve generating procedure includes generation of virtual data points from limited number of actual data points by bell curve implementation, determination of success/failure status of each data point by assigned criterion, and completion of final fragility curve. For practical applications, workability of concrete mixture content based on "unit water" has been used to obtain fragility curve. Detailed explanation of fragility curve drawing procedure for material parameters is presented.

In recent years, carbon fiber reinforced polymer(CFRP) has been widely used for reinforcement of damaged concrete structures. However, the fundamental mechanisms of load transfer and load-resistance for reinforced concrete beams retrofitted by CFRP are not fully understood. Acoustic emission(AE) technique was used to evaluate the characteristics of damage progress and the failure mechanism of reinforced concrete beams retrofitted by CFRP. In this study, three-paint-bending test has been carried out to investigate the AE characteristics of four specimens. The results show that the AE technique is a valuable tool to study the failure mechanism of reinforced concrete beams retrofitted by CFRP.

The properties of reinforcing fiber, as tensile strength, aspect ratio and elastic modulus, have great effect on the fracture behavior of HPFRCC(High performance fiber-reinforced cementitious composite). Acoustic emission(AE) method was used to evaluate the characteristics of fracture process and the micro-failure mechanism of HPFRCC. For these purposes, three kinds of fibers were used : PP(Polypropylene), PE(Polyethylene), SC(Steel cord). In this study, the AE characteristics of HPFRCC with different fiber type(PE.15, PP2.0, SC0.75+PE0.75) distributions under four-point-bending were studied. The result show that the AE technique is a valuable tool to study the failure mechanism of HPFRCC.

Superstructure of reinforced concrete bridges are shortened or elongated due to creep, drying shrinkage, temperature and so on. Most of bridge superstructures are free to shortening and elongation without constraint and stresses will not be induced by creep, drying shrinkage and temperature. But if bridge superstructure are constraint due to wrong setting and functional defects of bridge bearing, very large constraint forces can be induced. In this study, PSCI-Beam by tilt-constructed with constraint and deviation of bearings are presented and the effects of time-dependent constraint stress and temperature loads are investigated.

We enhance the stability of SaeManGeum Drainage Sluice Gate Bridge. We prevent a destruction disaster of it. We extend the life cycle of it. So We have developed the safety control system to manage the facility of bridge to the continuance. In this study, sensitive sensor and measuring instrument has been taken to consider the characteristic of the box-girder type concrete bridge. And CDMA type has adapted for wireless communication. Control program has been developed on web base. In this program, the advanced systems have applied like this; the setup of control range for management from the statistical analysis, the evaluation system for force and deformation and the control system for a heavy vehicle permit.

Recently, remodeling of the reinforced concrete apartment became hot issue of the housing policy in Korea. In Korea, the seismic design regulation has been revised since it was established in 1988 first, in order to minimize the economic losses. It has studied that the apartments that built in 1980's and their new remodeling for seismic performance. Also lateral displacement of remodeling analysis about variation of shear-wall for apartment on the architetural remodeling. Position change by wall quantity is state that study about efficient guide line about apartment wall quantity changed at remodeling because it is factor that can influence on motion of whole building is insufficient.

For giving self-diagnosing capability, a method based on monitoring the changes in the electrical resistance of carbon materials in strengthened concrete has been tested. Then after examining change in the value of electrical resistance of carbon materials used as a rib of CFGFRP or a sheet of carbon fiber before and after the occurrence of cracks and fracture in hybrid FRP or carbon fiber sheet strengthened concrete at each flexural weight-stage, the correlations of each factors were analyzed.

This paper presents a model for evaluating the contribution by arch action to shear resistance in shear-critical RC beams. Based on the relationship between shear and bending moment in beams subjected to combined shear and bending, The behavior of a beam is explicitly divided into two base components of the flexural action and the tied arch action. The compatibility condition of the shear deformation that deviates from Bernoulli bending plane is formulated utilizing the smeared truss idealization with an inclined compression chord. From this shear compatibility condition in a beam, the shear contribution by the arch action is numerically decoupled.

Deformability of RC members in shear is controlled by governing failure modes and material strength. Shear strength of members in D-regions has been explained by a direct load path (direct strut or arch action) and indirect load path (fan action or truss action). Indirect load path including truss action and fan action rely on bond along tension ties. Generally, superposition of two actions results in total shear strength when shear failure modes control. The ultimate deformation depends on controlling failure modes and thereby, their force transfer patterns. Proposed models are capable of explaining of limited deformability of RC members in D-regions.

According to current design provisions for shear strength of reinforced concrete slabs, critical slab sections around columns should be modified in the presence of openings in slabs to consider the effect of openings on the shear strength of slabs. Although the method of estimating the ineffective part of critical section due to openings are explained in codes, the real math for calculating it is somewhat complex and cumbersome. This paper classifies different cases of the location and geometry of columns and openings, respectively, and derives corresponding equations for estimating ineffective part of critical section for each case.

The measured longitudinal reinforcement tensions in the shear-critical RC beams were significantly higher than the calculated values by the beam theory. This may be attributed to the reduction of the internal-moment arm length by the development of the arch action. In this paper, the measured longitudinal reinforcement tensions in the test performed by Kim were compared with those predicted by the new truss model on the basis of the compatibility condition of the shear deformation.

Test results of four reinforced concrete two-span continuous deep beams are summarized. Main variables were the configuration of web opening reinforcement. Shear span-to-overall depth ratio and the size of the web opening were fixed by 1.0 and 0.5 a $\times$ 0.2 h, respectively. To control diagonal crack and enhance strength, it can be recommended that diagonal reinforcement crossing the crack plane joining between loading points and corner of openings should be provided.

Objective of this study is to understand the diagonal reinforcement around openings on the control of diagonal crack, load distribution, and ultimate strength of reinforced concrete two-span continuous deep beams. Test results of four specimens showed that the strength lost by openings might be completed when diagonal reinforcement ratio was above 0.0014.

Prestressed composite girder bridges with concrete infilled steel tube at negative flexural moment region takes the advantages of enhancing local buckling and flexural resistances resulting from the lateral confining effect of concrete due to the interactive reaction in the interface layer of steel tube and concrete. The interface behavior in concrete infilled tube of the test composite girder is analyzed by 8-node zero thickness interface finite element combined with 3-D. elastoplastic concrete constitutive model and 3-D. elastoplastic Mindlin shell element. The interface effects between infillled concrete and steel tube are investigated through the comparision of the experimental and numerical results.

LB-DECK is used for both of permanent formwork and structural component with cast-in place concrete of concrete bridge decks. Current Korean design code recommends that concrete bridge deck with precast concrete panels have to be designed only using conventional flexural design method and does not allow the empirical design method which is based on punching shear strength of bridge deck. This paper present experimental test results of punching shear strength of concrete bridge decks with LB-DECKs. Six full-scaled concrete bridge decks, which are designed with the empirical design method, are fabricated with variation of girder spacings. Test results are presented in the paper and compared with the code predictions of ACI 318, CEB-FIP MC90. Based on the test results, it is proposed that LB-DECK is suitable to apply the empirical design method for concrete bridge decks.

For checking fatigue safety and endurance of precast concrete deck and loop joint system in the steel plate girder composite bridge, the test composite bridge model was made for the fatigue experiment by the wheel load machine. The fatigue tests of 1,000,000 cycles were implemented according to wheel load condition of DB24 rear axle of Korea Highway Design Code. From the test results, the loop joint system for the precast deck has a sufficient flexural capacity. Although a little lower longitudinal continuity capacity is evaluated than general sound cast-in-place RC bridge deck, there is no problem about the safety. The overall fatigue level of safety defined by the code is satisfied.

This study investigates the behaviour of Hybrid Beam with reinforced concrete encased steel center and reinforced concrete end. Two types of encased steel shape and two sections are examined in this study. Test results showed that H-Hybrid beam is stronger than Honey-comb Hybrid beam, and the behaviour of composite beam embedded steel at the elastic state is same as that of simple beam.

Inner support regions of continuous steel and concrete composite bridge decks, transverse crackings are easely developed by tensile forces due to live loads and primary and secondary effects of concrete shrinkage. Since these cracks have an influence on the durability of bridge decks, crack width should be controlled within allowable limit values. Although crack width is a function of steel stress, bar diameter, bar spacing, etc, the current code for the amount of longitudinal reinforcements provides only one value of 2 percent of the concrete area. In order to investigate cracking bahaviors of composite girders with the variation of the longitudinal steel ratios, negative flexural tests are conducted on five composite girders and crack width and crack spacing are compared to ACI Code and Eurocode. Based on the test results, it is discussed the suitability of the current code for the longitudinal steel ratio.

Serviceability resign is required to control the cracking at the joint of precast decks having longitudinal prestress in continuous composite bridges. Especially, details of twin girder bridges are complex not only due to main reinforcements and transverse prestress for the resign of long-span concrete slabs but also due to shear pockets for obtaining the composite action. This paper suggests the design guidelines for the magnitude of the effective prestress and for the selection of filling materials and their requirements in order to use precast decks for twin-girder continuous composite bridges. The necessary initial prestress was also evaluated through the long-term behavior analysis. From the analysis, existing design examples were revised and their effectiveness was estimated. When a filling material having bonding strength higher than the requirement is used in the region of high negative moment, uniform configuration of longitudinal prestressing steels along the whole span length of continuous composite bridges can be achieved resulting in simplification of details and enhancement of the construction costs.

The ㄱ type perfobond rib shear connector is a ㄱ type flat steel plate with a number of holes punched through. This connector can be effectively used in girder with high shear. The ㄱ type perfobond rib shear connector exhibit very stiff behaviour under service load conditions and also had the characteristic of retaining a significant amount of load after the attainment of ultimate capacity. The ㄱ type perfobond rib shear connector with safety factor of 3 is applied shear connector of CFT composite girder. From static test result of CFT composite girder, relative displacement of 0.01mm measured at the service load moment. At design of the ㄱ type perfobond rib shear connector, applying safety factor of 3 was more conservative than test result.

In order to evaluate the shear strength of stud connectors in composite bridges using lightweight concrete decks, static push-out tests were performed. Sixteen push-out specimens were tested during this investigation. The test program consisted of two groups according to deck type, one is cast-in-place(CIP) concrete deck, the other is precast concrete deck. The experimental parameters were concrete compressive strength and bedding layer thickness. Based on the experimental results, the ultimate shear strength and the stiffness of shear connectors in lightweight concrete decks are assessed.

Appropriate analysis models for concrete-filled steel tube (CFT) subjected to bending moment were determined to assess flexural behavior of CFT member. Applying this model, finite element analyses was performed and compared against experimental data considering the compressive strength of in-filling material and the composite action between tube shell and in-filling core. Analysis results showed that the FE model proposed in this study is feasible for the analytical investigation of the flexural behavior of CFT member according to loading conditions, effect of compressive strength of various core materials and other design parameters.

AISC-LRFD, ACI 318 and Korean design specifications for concrete filled circular steel tube columns do not consider the increasing of axial stiffness such as the elastic modulus and the yield strength due to the confinement effect. AISC-LRFD and ACI 318, however, shows different basic philosophy and equations for computing the elastic modulus and the strength of CFT columns. Through this experimental study, 9 circular CFT column specimens were made by varying thickness steel tube and concrete strength, the axial stiffness were compared. The comparison between the design specifications and the test results shows different values on the elastic modulus and yield strength of the CFT columns. Even though, yield strength of the CFT columns are very similar between AISC-LRFD and Korean design specifications.

This paper focuses on the static behavior of prestressed and non-prestressed connections for the steel-concrete hybrid girder. Based on the experimental study, it is found that the girder with non-prestressed connection failed by local concrete failure at the connection area, and the studs are taken out from the concrete. In case of the girder with prestressed joint, the failure of the girder is initiated by the crack at the varying section area. The test results show that the girder with prestressed connection has higher load carrying capacity compare to the girder with non-prestressed connection by 12%. Therefore, the application of prestressing at the concrete-steel connection recommended for the more secure connection.

The reinforced concrete column confined by square steel tubes(RCST) is a reinforced column (RC) confined by thin steel tubes which cover over the full length of the column but terminates 15mm from the column's ends. The steel tube is in uniaxial tension stress state and won't buckle when the column sustains axial load. This will highly increase the bearing capacity and ductility of the columns. The hysteretic behavior of four square RCST columns and one square RC column were experimentally studied under constant axial load and lateral cyclic load. The wide-to-thickness (D/t) ratio of RCST columns employed in this research is 75. The main variables of the experiment were axial load ratio and compressive strength of the concrete. Based on the findings in this research, RCST columns exhibits high lateral strength, ductility, and energy dissipation ability.

Structures tend to become high-rise, large and specialized due to the urban concentration. Technology related to the structure and construction is required to improve, for which the use of high strength concrete(HSC) with better material property, and composite member with the combined advantage of both concrete and steel for better performance, is suggested. Over a half of fires, which increase by over 10% every year recently, come from the architectural structure, causing a loss at national level. However, little study has been conducted on the member at high temperature despite the increase in the use of HSC composite members. In this study, the techniques of modeling for analysing by DIANA (Displacement Analyzer) the fire damaged HSC composite compressive members are researched. We can review the effect of change in the steel ratio, section size and the steel ratio on the residual strength of structural members by parameter analysis study.

Since the behavior of structural members subjected to blast load shows different responses, the effect of impulse as well as peak load should be considered in the damage analysis. The threshold on P-I diagram that causes specific damage level divides the diagram into the failure zone and the non-failure zones. In this study, numerical analysis is performed based on single-degree-of-freedom (SDOF) techniques to generate rational P-I diagram considering material non-linearity and dual failure modes (flexure and direct shear) of RC beams. From the comparison with existing test results it is concluded that proposed numerical method is good to derive failure mode of RC beam under blast load.

This paper presents an analytical prediction of nonlinear characteristics and behavior characteristics PSC structures with un-bonded tendon system. In this paper, a numerical model for un-bonded tendon is proposed based on the finite element method, which can represent straight or curved un-bonded tendon behavior. this model and time-dependent material model used to investigate the time-dependent behavior of un-bonded prestressed concrete structures. The accuracy and objectivity of the assessment process may be enhanced by the use of sophisticated nonlinear finite element analysis program. A computer program, named RCAHEST(Reinforced Concrete Analysis in Higher Evaluation System Technology), for the analysis of concrete structures and steel plate was used. The material nonlinearities are taken into account by comprising the tension, compression, and shear models of cracked concrete and models for reinforcements and tendons in the concrete. The smeared crack approach is incorporated. It accounts for the aging, creep and shrinkage of concrete and the stress relaxation of prestressed steel. The proposed un-bonded tendon model and numerical method of un-bonded prestressed concrete structures is verified by comparison with reliable experimental results.

Several experimental investigations have been carried out to study the behavior of reinforced concrete columns with short lap splices. However, very few analytical models have been developed for the analysis of such columns subjected to earthquakes. As nonlinear analysis procedures become more common in practice (such as those outlined in the Guidelines for Seismic Rehabilitation of Buildings published by the Federal Emergency Management Agency in the United States), the need for an accurate and reliable representation of the nonlinear response of strength degrading systems becomes more important. In this study, an analytical model for estimating the complete response of reinforced concrete columns with short lap splices is presented. The model is based on local bond stress-slip relationships and is validated against independent experimental data from cyclic loading tests on reinforced concrete columns with typical construction details of the 1960s. In this paper a simple equation for calculating the bar stress at splice failure is presented. Use of the proposed equation resulted in excellent agreement between the measured and calculated strength at splice failure.

Coupling adjacent building with supplemental damping devices is a developing method of reduced structural response due to wind and seismic excitations. The philosophy is to allow structures, vibrating at different frequencies, to exert control forces upon one another to reduce the overall responses of the system. This paper studies the effect of installing vibration control devices of two high rise building structures(49 stories and 42 stories) connected by sky-bridge. According to the analysis results the use of sky-bridge can be effective in increasing damping ratio of the system.

This study presents a strut-and-tie model for the development of headed bars in an exterior beam-column joint with transverse reinforcements. The tensile force of a headed bar is considered to be developed by head bearing together with bond along a bonded length as a partial embedment length. The model requires construction of struts with biaxially compressed nodal zones for head bearing and fan-shaped stress fields against neighboring nodal zones for bond stresses along the bonded length. Due to the existence of transverse reinforcements, the fan-shaped stress fields are divided into direct and indirect fan-shaped stress fields. A required development length and head size of a headed bar can be optimally designed by adjusting a proportion between a bond contribution and bearing contribution.

Early age cracking of concrete is a widespread and complicated problem, and diverse applications in practical engineering have focused on this issue. Since massive concrete base slab composes the infrastructure of other concrete structures such as pier, concrete dam, and high rise buildings, early age cracking of that is considered as a crucial problem. In this study, finite element analysis (FEA) implemented with the age-dependent microplane model was performed. For a massive concrete base slab, cracking initiation and propagation, and deformation variation were investigated with concrete age. In massive concrete slab, autogenous shrinkage increases the risk of early age cracking and it reduces reinforcement effect on control of early age cracking. Gradual crack occurrence is experienced from exterior surface towards interior of the slab in case of combined hydration heat and autogenous shrinkage. FEA implemented with enhanced microplane model successfully simulates the typical cracking patterns due to edge restraint in concrete base slab.

This paper is aimed at proposing the sampling method to reduce variance of statistical parameters in uncertainty analysis of concrete structures. The proposed method is a modification of Latin Hypercube sampling method. This uses specially modified tables of random permutations of rank number. Also, the Spearman coefficient is used to make modified tables. Numerical analysis is carried out to predict the uncertainty of axial shortening in prestressed concrete bridge. The numerical results show that the method is efficient for uncertainty analysis of complex structural system such as prestressed concrete bridges.

This paper presents the structural characteristics of slab-column connections by using nonlinear finite element analysis. FEA considering material non-linearity was performed to investigate average column strain, failure mode, principal stress distribution, and steel yielding conditions for various slab-column members. In addition, to investigate alternative methods for improving the strength of interior column-slab joints, some specimens were provided with different reinforcing types of high-strength concrete puddling, high-strength column longitudinal steels, dowel bars, and high-strength concrete core. To make certain of the reliability of the analytical program, analysis results for concrete material model developed and two specimens with and without puddling were compared with experimental results. It was found that providing the alternative reinforcing methods in the slab-column joint results in a significant improvement in performance. This includes an increase in the axial compressive strength, greater loading stiffness, and ductility.

Past experiences from recent earthquakes indicate that shear failures of beam-column connections were one of the main reasons causing significant damages and collapses of RC structures subjected to earthquake loadings. Many researchers and engineers have conducted to propose an effective way to improve the joint shear strength of RC connections. This paper presents an analytical model for the RC exterior beam-column joints strengthened with CFRP sheets. In the analytical model, the effect of shear behavior of the RC beam-column joint, bond slip of the beam longitudinal reinforcements and CFRP sheets were considered and incorporated into the non-linear structural analysis program. Final analytical results were compared with those from the experiment of eight exterior RC beam-column specimens. The analytical results showed that the developed connection model is very useful to investigate the hysteretic joint behavior and overall load-displacement response of the RC beam-column connections strengthened with CFRP sheets.

To predict thermal stress independent of uncertain material properties of early age concrete, such as elastic modulus and creep, thermal stress device is used. In order to verify the application of various degree of constraint in the thermal stress device, a series of experiments were performed on mass concrete followed by numerical simulation. The application of various degrees of constraint can be achieved by using constraint frame material with different thermal expansion coefficient, length, and cross sectional area. Temperature development in the real structure has been simulated using temperature and humidity control chamber. The results from experiments and numerical analysis show that the thermal stresses estimated from simulation agree well with the general stress variations in the real structure even though the properties of concrete are uncertain.

Reinforced concrete shear wall is composed of wall, horizontal and vertical flanges. Due to the abrupt change in its geometry, it is difficult to predict the ultimate behaviour of shear wall in the action of lateral forces. For the better understanding of ultimate state, the propagation of crack and inelastic compressive zone are simulated reasonably. In this study, for the improvement of analysis result for shear wall with flanges, analyses are fulfilled with the application of some modelling methods including various material and geometrical models and numerical methods. The results from various modelling methods are compared and the advisable model is proposed.

The response of a reinforced concrete element under cyclic shear is characterized by the hysteretic loops of the shear stress-strain curves. These hysteretic loops can exhibit strength deterioration, stiffness degradation, and a pinched shape. Recent tests have shown that the orientation of steel grids in RC shear elements has a strong effect on the "pinching effect" in the post-yield hysteretic loops. When the steel grid was set at a 45 degree angle to the shear plane, there was no pinching effect and no strength deterioration. However, when the steel grid was set parallel to the shear plane, there was a severe pinching effect and severe strength deterioration with increasing shear strain magnitude. In this paper, two RC elements subjected to revered cyclic shear stresses are considered to study the effect of the steel grid orientation. The presence and absence of the pinching mechanism in the post-yield shear hysteretic loops is studied using the Rotating Angle Softened Truss Model (RA-STM) theory.

This paper presents a newly proposed object-oriented finite element framework and its applications on dynamic analysis of plate girder bridge. The developed framework supports various types of finite elements, materials, constraints, loads, and solution methods. One major feature different from other object-oriented finite element programs is that static model and dynamic state can be easily read from or written to a file. In addition, the framework supports efficient DOF pattern handling for a node connecting elements with different DOF patterns, new multi-point constraint handling, and various scripting languages for easy use of the library. In order to show the applicability to dynamic analysis, dynamic moving load analysis on plate girder bridge is performed.

The purpose of this study is to investigate the inelastic behavior of reinforced high-strength concrete bridge columns. A computer program, named RCAHEST (Reinforced Concrete Analysis in Higher Evaluation System Technology), for the analysis of reinforced concrete structures was used. Material nonlinearity is taken into account by comprising tensile, compressive and shear models of cracked concrete and a model of reinforcing steel. The smeared crack approach is incorporated. The increase of concrete strength due to the lateral confining reinforcement has been also taken into account to model the confined high-strength concrete. The proposed numerical method for the inelastic behavior of reinforced high-strength concrete bridge columns is verified by comparison with reliable experimental results.

The objectives of this study are to develop and evaluate the Neural Network algorithm which can predict the inelastic shortening such as the creep strain and the drying shrinkage strain of reinforced concrete members using the previous test data. New learning algorithms for the prediction of creep strain and the drying shrinkage strain are proposed focusing on input layer components and a normalization method for input data and their validity is examined through several test data. In Neural Network algorithm, the main input data to be trained are the compressive strength of the concrete, volume to surface ratio, curing condition, relative humidity, and the applied load. The results show that the new algorithms proposed herein successfully predict creep strain and the drying shrinkage strain.

R.C. Rahmen bridges have been widely constructed in the location of interchange or narrow road crossing. In addition, skewed or curved rahmen bridges are mostly constructed in comparison with normal rahmen bridges for the purpose of maintaining the route of road or considering the beauty of bridge. However, due to the functional characteristics, rahmen bridges are sustained under the direct vehicle loads and the side directional earth pressure so that the stress concentration with respect to the geometrical eccentricity can be occurred if rahmen bridges are constructed in large amount of skew. In this investigation, the behavior of skewed rahmen bridges which is located in curved route has been analysed to investigate the additional effects on the change of stress concentration. As a result, it is judged that the stress of curved rahmen bridges is more concentrated than the stress of straight rahmen bridges in the region of obtuse angle. However, in the middle of slab, the curve does not affect on the stress concentration.

The Purpose of this study is to offer an appropriate and reliable safety evaluation method the reinforced concrete members like as reinforced concrete deep beams and reinforced concrete columns, etc. A nonlinear finite element analysis program named RCAHEST (Reinforced Concrete Analysis in Higher Evaluation System Technology) was used to evaluate the ultimate strength analytically for the reinforced concrete members that have complicated mechanical behaviors. The nonlinear material model for the reinforced concrete is composed of models for characterizing the behavior of the concrete, in addition to a model for characterizing the reinforcing bars. The proposed numerical method for the safety evaluation of reinforced concrete bridge structures that is consisted of reinforced concrete member is verified by comparison with reliable experimental results.

Extended Kalman Filter iterate the prediction and the filtering based on Initial state for the next time step. EKF method for the estimation of nonlinear parameters of a structural dynamic system is necessary that initial of state vector and error covariance matrix. Because those are unknown exactly, generally selected random values. That occasion observability problem appear because of unknown initial values. In this study, for the estimation of the nonlinear parameters, a simple one degree of Freedom example is carried out by Extended Kalman Filter. And initial value assumption for Parameter Estimation of Dynamic System are developed. The result of analysis is compared with calculated standard values.

Due to the location of vibration sensitive equipment on the floor, it is necessary for its vibration performance to be maintained within stringent limits, resulting in a design of higher mass and stiffness than would be usual for a floor of this type. Modal testing is conducted on the floor to obtain their dynamic characteristics. A considerable level of vibration transmission is observed by comparing the ratio of simulated transfer and point mobility FRFs of the floor.

Nonseismic designed RC frame have a possibility of shear failure because of deficiencies of reinforcing details. To model the shear failure in numerical analysis, shear strength degradation models which include Moehle's and ATC 40 are compared and applied to push-over analysis. For numerical analysis, three storied building frame is selected and designed according to Korean Concrete Design Code(2003). From the numerical analysis, it is pointed out that there may be great difference in lateral drift capacity if a different shear strength model is used. And the capacity can be severely underestimated if the restraining model of plastic rotation of ATC 40 is used, compared to the use of shear spring for shear degradation.

The purpose of this study is to evaluate structural performance of concrete beam reinforced simultaneously with GFRP and steel rebar. Because the GFRP has lower elastic modulus than steel or CFRP, serviceability for concrete structure can be an issue. According to the test result, the hybrid reinforced specimen showed better stiffness improvement than the specimen reinforced with only GFRP rebar. From an additional research on design parameter and reliability analysis, the field adaptability can be proved.

This study is intended to discuss the application of blast slag for concrete to improve the durability of precast concrete box culvert. The precast concrete box culverts with blast slag are tested to verify the effect of early strength. The results show that the initial cracking load and yielding load of the blast slag concrete members are increased when they are compared with those of the normal concrete. In the prototype precast concrete box culvert experiment, initial crack control effect and ductility index are increased. It can be concluded that the use of blast slag was improved the durability in precast concrete box culvert.

In this paper, flexure behavior of steel fiber reinforcement ultra high performance cementations composites (SFR-UHPCC) has been analyzed by equivalent stress block. Pulling-out tensile force of steel fiber with concrete matrix was induced. An appropriate flexure evaluation formula, i.e. semi-analytical formula, was established based on rectangular cross section beam for comparing with shear capacity and ultimate load of SFR-UHPCC beam. Finally, the semi-analytical formula has been simplified for the convenience of design work. Experimental results and theoretical shear strength are shown to compare with the formula proposed by this paper. The theory formula has a good prediction of failure type of SFR-UHPCC.

This thesis investigates the behavior of precast wall systems with a new vertical connection which are proportioned by the displacement based design. The proposed precast wall systems are supposed to provide additional spaces and seismic strengthening in remodeling existing residential buildings. For a fast remodeling constructions using PC walls require an efficient, economic fabrication method. A C-type vertical connections for PC wall systems is proposed for transfer of bending moment between walls in the vertical direction while a shear key in the center of wall is prepared to transfer shear forces by bearing. The proposed vertical connection allows us easy fabrication because of different direction of slots at the edges of wall. The dimension of C-type connection components are determined by engineering models and a series of test.

The jacking of cantilever before key segment closure has been introduced to offset the long term forces caused by creep and shrinkage. In this paper, the behavior of structural system with the jacking force in approach bridge of Incheon Bridge was reviewed. The introduction of jacking force effectively offset the long term horizontal forces and allows economic substructure member design.

PSC(Prestressed Concrete) box girder bridges have been widely applied in Korea. A number of these bridges have been built by the segmental construction method in the longitudinal direction and(or) vertically along the cross-sectional depth with MSS(Moving Scaffolding System). An actual 2-span continuous PSC box girder bridge of Kyeongbu high speed railway was selected and instrumented with 96 vibrating wire embedded type strain gauges and 2 thermocouples. The long-term behavior of the bridge was monitored through two major points located at mid-span of the first span and at the internal support. Data collection started just after the casting of the first segment (U section). Concrete strain and temperature data were gathered regularly by a data logger (CR10) during 600 days under and after construction. According to this measurement, the parabolic longitudinal strain distribution in the top slab at mid-span is shown. And also, the same distribution at the interior support is shown. The compressive strains at the cantilever region are larger than at the web position and the internal part in the top slab. Strain difference largely happened during the early construction period.

In the domestic atmosphere environment, the VOCs and the NOx have a large proportion of the pollutant, and the HCHO is the main environmental pollutant factor within the house. In this study, the inorganic paint which can absorb and remove VOCs, NOx and HCHO is developed by using day-titania carrier. The basic data to develope eco-friendly inorganic paint is collected with the performance test to remove the VOCs, NOx and HCHO in the condition of the addition of several inorganic materials to the paint, and also the plan to practical use of eco-friendly inorganic paint is studied.

A series of seismic tests was carried out using piezoelectric elements called "bender elements". A pair of bender elements can be used as a source and a receiver respectively to measure dynamic properties of concrete. The most suitable bender elements were developed and implemented to measure P wave velocity changes due to the cracks of a concrete beam caused by bending.

This study measured corrosion rates for checking and analysis of Hume pipes in the housing sites. According to the result, Concrete pipe is deteriorating for twenty years by hydrogen sulfide(H2S). Investigation method applied phenolphthalein method(depth of neutrality). Phenolphthalein method measured average depth from concrete surface to coloring point by red after spraying phenolphthalein solution. A result of investigation, Life span of Hume pipe in the housing site is investigated of twenty years.

For various historical and technical reasons, the safety of dams has been controlled by an engineering standards-based approach, which has been developed over many years, initially for the design of new dams, but increasingly applied over the past few decades to assess the safety of existing dams. And some countries were asked for risk assessment on existing dam, which included structural, hydraulic safety of dam and social risk. Whereas other countries have developed and adapted as an additional tool to assist in decision-making for dam safety management. Dam risk analysis should need the reliability data of dam failures, the past constructed history and management records of existing dam. It is thought with risk analysis method of dams for structural safety management in domestic that suitable to use consider an event tree, fault tree and conditioning indexes method.

In many case, reinforced concrete structures are deteriorated by construction errors, design errors, settlement and movement, and weathering. The diagnose and repair of concrete deterioration is important for effective management of concrete structures. This manual is to provides guideline on evaluating the deterioration of the concrete in a structure and selecting an appropriate repair material and method.

Recently, the public interest for infrastructure safety has been growing, but the process of data acquisition and management system for safety is being carried out in an inefficient manner. The data obtained during the inspection for the safety of infrastructure tends to be documented using papers, which is not efficient in the stage of post analyses. The information technology (IT), which is rapidly being developed, is applied to the new system as a solution. Information technology provides valuable tools for converting and generating digital data, handling the history of defects, and assessing the condition and estimating the service life of infrastructure. The purpose of this paper is to introduce Infrastructure Management System(IMS). It is expected that the IMS would minimize the manpower, time and maintenance cost, and improve the safety of infrastructure.

The purpose of this study is to develop digital air meter used pressure sensor for measurement of air content in freshly mixed concrete by pressure method. The digital air meter can enhanced measurement accuracy and uniformity of air content in freshly concretes, according to use of pressure sensor and measuring process automation. Finally, the digital air meter in this study is improved reproducibility and reliability of measurement compared with analog air meter.

It is proposed that the electromechanical relation of the conductive materials with high electrical resistance may be used to estimate the current stress of prestressing tendons. To choose the best conductive material to this end, we studied the electromechanical relations of carbon fibers and metalic heat wires experimentally. It is found that the relation of carbon fibers can be modelled by a parabolic(or hyperbolic) function in the early stage of deformation. Metallic heat wires show a consistent linear relation during loading and unloading in the elastic deformation and are suitable for this purpose. We propose a new kind of prestressing tendons whose stress can be monitored.

Recently, the deterioration due to salt damage and carbonation as the main factors of deteriaoration of the domestic reinforced concrete structures has been increased. Also the national and social concern about the durability recovery of the deteriorated reinforced concrete structures is geratly being raised. Therefore, it is the final purposes of this study to develop the performance evaluation technique for durability of reinforced concrete structures deteriorated due to salt damage and carbonation with the proposal of the service life prediction method for the investigation and diagnosis of reinforced concrete structures, and accelerated test in Lab.

This study was performed to develop acid-soluble extraction solution and water-soluble extraction solution for hardened concrete. By use of this potentiometric method one can determinate chloride ion concentration in hardened concrete without pre-treatment and it can be used on-site.

Recently, many methods to evaluate the water content in concrete were developed. In this study, using a commercially avaliable equipment by the unit volume weight method, the water content in concrete was estimated when the moisture content in sand was changed. In order to evaluate the accuracy and the usefulness of the method, the designed water content and the measured water content were compared. The compressive strength of concrete with the variation of moisture content in sand was measured as well. As a result, it appears that in order to predict the water content in concrete, the adjustment coefficient of aggregate should be exactly estimated. It is shown that the equipment tends to underestimate the water content in concrete.

Recently, the application area of wireless LAN(Internet) and CDMA have been increased, rapidly. Bridge monitoring system using this ubiquitous Computing Technology can bring more convenience of bridge maintenance and management. This paper present a automatic data acquisition, control and processing technology through this concept, and check system applicability to the concrete bridge completed. Finally, The preventive bridge monitoring through the application of this system will progress in technology and make civil infrastructure more safe and useful.

Waterproof performance for water suitableness part prove. Being to know change about performance by oil and waterproof shape by this, must study and examine an experiment about whether concrete displays effect that is based of oil when waterproof lost performance and wish to examine effect to get in the construction.

Chloride ion penetration and carbonation are the most important factors in the durability problems of reinforced concrete structures. Most of the existing studies on those subjects are focused on the no-crack concrete, though the existence of crack may strongly affect the chloride ion penetration and carbonation. To evaluate the influence of crack on the chloride ion penetration and carbonation and to assess the service life of reinforced concrete more accurately, finite volume analyses (FVA) were performed based on the FV mesh containing the ideal crack whose width is uniform along the depth. Analytical results show that the influence of crack width and depth is much more pronounced for the chloride ion penetration than for the carbonation.

The Purpose of this study is to develope the method for early recovery of the biodiversity in the oligotrophical costal area, it is important in the recovery of the biodiversity to make kelp forest grow in the concerned area. In order for it, sufficient nutrient is required as well as the proper seedbed, Hence in this study, granulated fertilizer, which contains nutrient, such as nitrogen, phosphorus and etc, is coated by cement paste, and then is mixed in to the porous concrete in order to provide seedbed and nutrient simultaneously. As a result of examination of growth property of marine plants of multiple performance concrete for kelp forest regeneration, seaweeds is adhered plentifully when the number of days is longer. when the granular fertilizer mixed. adherence and growth of marine plants is excellent and is stabilized over the long run. In case 6 month of the number of days immersed, marine plants and growth will appear.

Locating reinforcing bars, in particular to know their accurate depths and horizontal distances, is very important in radar inspection of concrete structures. By the way, it is not easy for an accurate depth and horizontal distance estimation of reinforcing bars in concrete structures by the radar test. This problem can be solved by synthetic aperture radar method. To improve the vertical and horizontal resolution of reinforcing bars in concrete, synthetic aperture radar method was examined in this study.

In this study, it was selected that in order to make an investigation into the status of the unit water content control of the ready-mixed concrete plants in the country, Capacitance Measurement Method out of various methods which are able to gauge the amount of unit water content in fresh concrete. Then, it were estimated that the quantity of unit water in fresh concrete and the technical standard of every mixture design of the six ready-mixed concrete plants chosen at random in the country. Finally, based on this study, it was proposed as fundamental data to utilize measurement techniques of the quantity of unit water for the quality control of the ready-mixed concrete in construction field.

This paper is the fundamental study for manufacture of spalling resistance concrete and also analyses the mechanism and spalling resistance method with materials, mixture proportion and lateral confinement. The present work with the basic experiment achieved successful method for spalling resistance using both proper amounts of fiber contents and lateral confinement using metal lath. Moreover, the developed spalling resistance method was applied for full sized column construction in the Doosan We've Poseidon I field, located in Busan city. Authors investigated the physical properties examining workability, placeability and pumpability. These studies are continuously processing to develop new technology expecting remarkable impact on the spalling resistance and fire resistance performance of high-raise building construction in the future.

This study investigates the quality control and the finishability improvement properties of durable marine concrete under construct in Geo-je Ka-duk fixed link project. Below $3.5\times10^{-12}m^2/s$ chloride migration coefficient and above 40MPa compressive strength are required for the caisson structure concrete. The quality control was performed from physical-chemical analysis of raw materials to concrete test. Also, the efficiency of vibration type and action interval were tested to remove the entrapped air on the faced to form. And kinds of form and remolding agent were also tested. This paper aim to enhance the practical use of high performance concrete to construction field.

This paper is to investigate temperature history of cold weather concrete depending on insulation curing sheet kinds. Insulating effect according to curing sheet is shown in order of 5 layer bubble sheet, combination of PE form and 3 layer bubble sheet and 3 layer bubble sheet. It maintained above $10^{\circ}C$ of minimum temperature until the completion of initial curing period when bubble curing sheet was supplied regardless of curing sheet kinds. Five layer bubble curing sheet secure higher curing temperature than any other curing sheet applied in this experiment by as much as $2{\sim}3^{\circ}C$, which performed remarkable insulation effect. Concrete applied with curing sheet secured above $65^{\circ}D{\cdot}D$ of maturity, at which concrete had 5MPa of compressive strength at 3 days.

This Study is the consideration for new formwork assembly method in Bearing Wall System. It is consisted of two parts. one is researched into an ordinary formwork system and suggested a new formwork system. The other makes an investigation into the resisting capacity of proposed method by experimental and field test. For the application of this method to the field, it is expected to improve workability and safety, and to reduce the loss of labor.

Suk-San highway bridge, located on a soft ground environment, had been examined the current condition of settlement estimation throughout G.P.R(Ground Penetrating Radar), general observation and visual observation(video camera & scope). According to the above observations, the ground of this area has sunk about thirty centimeters since 1996. Also, currently, Suk-San highway bridge has been disjoining the gap between the structure and ground. Therefore, it is necessary to fill it up the gap. The purpose of this paper is to report the effects of Sunk-San highway bridge was observed by G.P.R. & general observation etc. and to present the results of repair of Suk-San highway bridge filling the gap up.

In this study, we concerned the steel cap and head part arrangement of PHC pile structure to complement existing construction process which have the defects such as highly hazardous circumstance for safety concerns and retard a term of works. The steel cap developed for supplement the stiffness between extend foundation and contact section of PHC pile that is based on structural theory. The experiments have been performed to evaluate the characteristics of behavior between head part of PHC pile using steel cap and extend foundation.