• Title, Summary, Keyword: Slab joint

Search Result 199, Processing Time 0.04 seconds

A Study on the Shear performance of Joints for slab extension (슬래브확장을 위한 접합부의 전단성능에 관한 연구)

  • Ryu, Han-Gook;Park, Tae-Won;Chung, Lan;Lee, Sang-Hyun
    • Proceedings of the Korea Concrete Institute Conference
    • /
    • /
    • pp.109-110
    • /
    • 2009
  • This study is to evaluate the shear performance of joint between existing and new slab in apartment remodeling construction for enlarging existing slab. The horizontal joint parameters are consisted by steel pipe cotter, shear reinforcement, H-steel, stud bolt, and round shear key by concrete. And joint specimens will be tested to evaluate the shear performance of these parameters. If the joint detail have sufficient strength, it will be proposed the basic form on the design of joint parts.

  • PDF

Optimal Joint Position in Concrete Pavement Slab over Skewed Box Culvert (수평으로 경사진 박스암거 위 콘크리트 포장 슬래브의 최적 줄눈위치)

  • Yeom, Woo Seong;Jeong, Ho Seong;Yan, Yu;Sohn, Dueck Soo;Lee, Jae Hoon;Jeong, Jin Hoon
    • International Journal of Highway Engineering
    • /
    • v.15 no.5
    • /
    • pp.47-55
    • /
    • 2013
  • PURPOSES : The purpose of this study is to investigate the optimal joint positions which can minimize distresses of concrete pavement containing box culvert with horizontally skewed angles. METHODS : The concrete pavement containing the box culvert with different skewed angles and soil cover depths was modeled by 3 dimensional finite element method. The contact boundary condition was used between concrete and soil structures in addition to the nonlinear material property of soil in the finite element model. A dynamic analysis was performed by applying the self weight of pavement, negative temperature gradient of slab, and moving vehicle load simultaneously. RESULTS : In case of zero skewed angle ($0^{\circ}$), the maximum tensile stress of slab was the lowest when the joint was positioned directly over side of box culvert. In case there was a skewed angle, the maximum tensile stress of slab was the lowest when the joint passed the intersection between side of the box culvert and longitudinal centerline of slab. The magnitude of the maximum tensile stress converged to a constant value regardless the joint position from 3m of soil cover depth at all of the horizontally skewed angles. CONCLUSIONS : More reasonable and accurate design of the concrete pavement containing the box culvert can be possible based on the research results.

Quantitative Estimation of Joint Spacing for Concrete Slab to Prevent Cracking of Drying Shrinkage (건조수축에 따른 균열 방지를 위한 콘크리트 슬래브의 정량적 줄눈 간격 산정)

  • Lee, Su-Jin;Lee, Hoi-Keun;Lee, Seung-Hoon;Won, Jong-Pil
    • Journal of the Korea Concrete Institute
    • /
    • v.23 no.3
    • /
    • pp.289-294
    • /
    • 2011
  • The installation of joint is to prevent random cracking due to drying shrinkage stress of concrete slab. However contraction joint spacing is empirically implemented into slab constructions without detail calculation based on quantitative criteria. In this study, shrinkage strain of concrete due to concrete shrinkage stress was measured to suggest joint spacing based on the study results. The test environmental conditions were applied temperature of $15^{\circ}C$ and relative humidity of 60%. The design compressive strength used was 30 MPa and 40 MPa, which are currently used in concrete slab designs. The drying shrinkage test result was applied to drying shrinkage models (ACI 209R, CEB MC 90, B3, GL 2000 and Sakata). The results showed that the most appropriate model was ACI 209R model. Based on the research findings, quantitative contraction joint spacing locations were calculated.

Experimental Study on Shear Capacity of I-slab System Using Slim Precast Slab Deck (슬림 프리캐스트 슬래브 데크를 사용한 I-슬래브 시스템의 전단 성능에 관한 실험적 연구)

  • Kim, Seung-Hun
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.21 no.1
    • /
    • pp.126-133
    • /
    • 2017
  • This paper presents the shear capacities of hollow slab with plate and octagonal pillar type hollow sphere. Recently, the interest in precast hollow slab system for buildings is growing up according to the demand for high quality control and the increase in slab thickness. A hollow slab system is widely known as one of the effective slab system which can reduce self-weight of slab. However, hollow slabs are vulnerable to the deterioration in the shear strength due to the decrease of concrete at slab web which resists shear. Especially, in case of precast hollow slabs, it has joint surface between precast concrete slab modules along transverse axis of slab, and shear failure, that is caused by cracks at joints, has to be prevented. Therefore, in this study, shear capacity of the I-slab system is evaluated by 3-points-supported shear test along the longitudinal and transverse axis of slab specimen. Test results showed that I-slab had enough shear strength compared to theoretical shear strength even if it included the joint surfaces.

Hysteretic Behavior of Slab-Column Joint Using Bended Type Shear Reinforcement (절곡형 전단보강근을 사용한 슬래브-기둥 접합부의 이력 거동)

  • Lee, Hyun-Ho;Lee, Do-Bum;Lee, Li-Hyung
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.10 no.3
    • /
    • pp.211-218
    • /
    • 2006
  • From the development of residential flat plate system, continuously bended shear reinforcement is developed for the prevention of punching shear. To know the punching shear capacity of developed shear reinforcement in slab-column joint, structural test is performed. The testing parameters are shear reinforcement types, such as no reinforcement, bended shear reinforcement, and head stud reinforcement. To verify the lateral capacity, cyclic load is applied under the constant vertical load condition. The results of tests are compared to as global displacement, slab-column joint strength. From the test results, the resisting capacity of developed shear reinforcement system has a good performance in the story drift ratio.

Cyclic behaviour of concrete encased steel (CES) column-steel beam joints with concrete slabs

  • Chu, Liusheng;Li, Danda;Ma, Xing;Zhao, Jun
    • Steel and Composite Structures
    • /
    • v.29 no.6
    • /
    • pp.735-748
    • /
    • 2018
  • In this paper, the cyclic behavior of steel beam-concrete encased steel (CES) column joints was investigated experimentally and numerically. Three frame middle joint samples with varying concrete slab widths were constructed. Anti-symmetrical low-frequency cyclic load was applied at two beam ends to simulate the earthquake action. The failure modes, hysteretic behavior, ultimate load, stiffness degradation, load carrying capacity degradation, displacement ductility and strain response were investigated in details. The three composite joints exhibited excellent seismic performance in experimental tests, showing high load-carrying capacity, good ductility and superior energy dissipation ability. All three joint samples reached their ultimate loads due to shear failure. Numerical results from ABAQUS modelling agreed well with the test results. Finally, the effect of the concrete slab on ultimate load was analyzed through a parametric study on concrete strength, slab thickness, as well as slab width. Numerical simulation showed that slab width and thickness played an important role in the load-carrying capacity of such joints. As a comparison, the influence of concrete grade was not significant.

Continuity for Double Tee Slabs (더블티 슬래브의 연속화)

  • 유승룡
    • Journal of the Korea Concrete Institute
    • /
    • v.13 no.2
    • /
    • pp.99-106
    • /
    • 2001
  • The main objective of this study is to develop a continuity of double tee slab with two modified dap-ends to solve the problems of excessive moment, slab depth, deflection, and joint cracking in the original simply supported double tee slab systems. The modified joint is produced in a combination with two slabs with modified dap and one rectangular beam. The modified joint can be justified as following different merits. The span capacity for a design load is increased, while the deflection of the slab is decreased due to the decrease of positive moment at the center span of the slab. The joint cracking between slab and beam, which occur frequently in the original slab systems of double tee will be reduced. No more additional form work is needed to cast topping concrete for continuity. Three point loading tests are performed on the specimens with a variable of an amount of main longitudinal reinforcement to evaluate flexural and shear behavior. Following conclusions are obtained from the experimental investigation. The continuity of double tee slab effectively is provided by placing longitudinal steel reinforcement in the topping concrete over the connection, and generally leads to an increase in span capacity of double tee slabs with reduced deflection. It is more effective to control the initial cracking at the connection than that of some simply supported double tee slab systems.

The Minimum Lap-spliced Length of the Reinforcement in the Steam Curing UHPC Bridge Deck Slab Joint (UHPC 바닥판 증기양생 현장이음부의 최소철근겹침이음길이)

  • Hwang, Hoon-Hee;Park, Sung-Yong
    • Composites Research
    • /
    • v.26 no.2
    • /
    • pp.135-140
    • /
    • 2013
  • The static test was performed to verify the effect of the joint in the UHPC bridge deck slab and the minimum lap-spliced length was presented. A total of six test members was fabricated to estimate the static behavior of the steam curing UHPC bridge deck slab joint by the four points bending test method. The lap-spliced joint type was expected to be not only simple but also efficient in UHPC structure because of the high bond stress of UHPC. Test results show that the decrease of maximum flexural strength was about 30% and the minimum lap-spliced length which behaved similar to the continued reinforcement in strength and ductility was 150 mm.

Behavior of composite CFST beam-steel column joints

  • Eom, Soon-Sub;Vu, Quang-Viet;Choi, Ji-Hun;Papazafeiropoulos, George;Kim, Seung-Eock
    • Steel and Composite Structures
    • /
    • v.32 no.5
    • /
    • pp.583-594
    • /
    • 2019
  • In recent years, composite concrete-filled steel tubular (CFST) members have been widely utilized in framed building structures like beams, columns, and beam-columns since they have significant advantages such as reducing construction time, improving the seismic performance, and possessing high ductility, strength, and energy absorbing capacity. This paper presents a new composite joint - the composite CFST beam-column joint in which the CFST member is used as the beam. The main components of the proposed composite joint are steel H-beams, CFST beams welded with the steel H-column, and a reinforced concrete slab. The steel H-beams and CFST beams are connected with the concrete slab using shear connectors to ensure composite action between them. The structural performance of the proposed composite joint was evaluated through an experimental investigation. A three-dimensional (3D) finite element (FE) model was developed to simulate this composite joint using the ABAQUS/Explicit software, and the accuracy of the FE model was verified with the relevant experimental results. In addition, a number of parametric studies were made to examine the effects of the steel box beam thickness, concrete compressive strength, steel yield strength, and reinforcement ratio in the concrete slab on the proposed joint performance.

Static Load Tests on Flexural Strength and Crack Serviceability of a Longitudinal Joint for the Slab-Type Precast Modular Bridges (슬래브 형식 프리캐스트 모듈러교량 종방향 연결부의 휨강도 및 균열 사용성에 관한 정적재하실험)

  • Lee, Jung-Mi;Lee, Sang-Yoon;Song, Jae-Joon;Park, Kyung-Hoon
    • Journal of the Korea Concrete Institute
    • /
    • v.27 no.2
    • /
    • pp.137-145
    • /
    • 2015
  • The slab-type precast modular bridge consists of the precast slab bridge modules which are connected in the transverse direction. The longitudinal joints between the precast slab bridge modules are filled with cast-in-place mortar. The construction of the slab-type precast modular bridge is completed by applying the prestressing force on the longitudinal joints. In this study, 4-points bending tests and 3-points bending tests were conducted to examine the effects of the prestressing force and the shape of joint on the flexural strength and crack serviceability of longitudinal joint. The results of 4-points bending tests showed that the flexural strength is affected by the prestressing force but not by the shape of join. From the results of 3-points bending tests by which the bending moment and the shear force are simultaneously applied on the joints of the specimens, it is observed that the shape of joint affects on the flexural strength and the crack behavior. The results of two types of bending tests confirmed that the prestressing force according to the design code is appropriate and the joint with two shear keys gives the better performances against the crack of joint.