• Advances in concrete construction
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• 제8권2호
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• pp.139-144
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• 2019

In this study, the mechanical properties of reactive powder concrete (RPC) with a constant cement to silica fume ratio of 4 were investigated. In the experimental program, reactive powder concretes with steel fiber at different ratios were produced. Five productions using quartz sand with a maximum grain size of 0.6 mm were performed. A superplasticizer with a ratio of 3% of the cement was used for all productions. $40{\times}40{\times}160mm$ prismatic specimens were prepared and tested for flexural and compression. The specimens were exposed to two different curing conditions as autoclave and standard curing condition. Autoclave exposure was performed for 3 hours under a pressure of 2 MPa. It was observed that the compressive strength of concrete, along with the flexural strength exposed to autoclave was quite high compared to the strength of concretes subjected to standard curing. The results obtained indicated that the compressive strength, along with the flexural strength of autoclaved concrete increased as the amount of cement used increases. Approximately 15% increase in flexural strength was achieved with a 4% steel fiber addition. The maximum compressive strength that has been reached is over 210 MPa for reactive powder concrete for the same steel fiber ratio and with a cement content of $960kg/m^3$. The relationship between compressive strength and flexural strength of reactive powder concrete exposed to both curing conditions was also identified.

• Computers and Concrete
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• 제4권6호
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• pp.425-436
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• 2007

This study is mainly focused on applying Fuller's ideal gradation curve to theoretically design blended ratio of all solid materials of a reactive powder mortar (RPM), also known as reactive powder concrete (RPC), with the aid of error function, and then to study the effect of fly ash/slag on the performance of RPM. The solid particle is assumed to be spherical particles. Then, the void volume of paste ($V_{\nu}$) and the paste content with specific quality can be obtained. As conclusion, under Fuller's ideal grading curve, the amount of fly ash/slag mixture is higher than that with silica fume along due to it better filled the void within solid particle and obtains higher packing density.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2013년도 추계 학술논문 발표대회
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• pp.74-75
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• 2013

The paper study on the mechanical properties of reactive powder concrete using copper slag. A change in the replacement ratio s of copper slag was measured compressive strength and slump flow. As a results, slump flow using copper slag tend to increase slump flow with replacement ratio. As the concrete with a replacement ratio of copper slag up to 30% was found to have a compressive strength superior to that of plain.

• 한국세라믹학회지
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• 제47권5호
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• pp.419-425
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• 2010

In order to examine the P.H.C pile raw material using glass forming ceramic. The used materials is ordinary portland cement, waste TFT-LCD glass powder and reactive agent(Ca$(OH)_2$). The first experiment is characteristics analysis of the waste TFT-LCD glass powder, For the second experiment is mortar and concrete compressive strength for using of the concrete file raw material for waste TFT-LCD glass powder. The results of experiment showed that the substitution ratio of 10% waste TFT-LCD glass powder and 1% reactive agent(Ca$(OH)_2$) was excellent at a point of view for the physical characteristic. The study's most important finding is that the recycling of waste TFT-LCD glass powder.

• Steel and Composite Structures
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• 재36권6호
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• pp.657-669
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• 2020

This study investigates the fire resistance characteristics of reactive powder concrete according to changes in the cement content per unit area, mixing ratio of metakaolin (MK), and content of polypropylene fiber. A fire test was conducted, and the resulting residual strength characteristics were investigated through flexural and compressive strength measurements, as well as condition rating classification based on visual evaluation. MK effectively reduced the initial high content of calcium hydroxide, thereby reducing the water vapor pressure generated during pyrolysis and slowing spalling. Furthermore, the pore structure and loose tissue were effective for relieving the water vapor pressure in the event of a fire.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2014년도 춘계 학술논문 발표대회
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• pp.278-279
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• 2014

This study was performed an evaluation of mechanical properties of reactive powder concrete using copper slag. So, various RPC containing copper slag were made by replacement ratio of copper slag and different the curing condition and their mechanical properties were investigated. From the experimental results, slump flow using copper slag tends to increase with replacement ratio. And also, 30% of copper slag with quartz sand was found to have a compressive strength superior to that of plain.

• 한국건축시공학회지
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• 제13권1호
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• pp.48-57
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• 2013

To consider the practicality and economic feasibility of developing reactive powder concrete (RPC), the strength and microstructure properties of RPC using ternary pozzolanic materials (silica fume, blast furnace slag, fly ash) were investigated in this study. Through the investigation, it was found that the compressive strength of RPC using ternary pozzolanic materials was increased significantly compared to that of the original RPC containing silica fume only. A considerable improvement in the flexural strength of RPC using ternary pozzolanic materials was found, and then the utilization of a structural member subjected to bending was expected. The X-ray diffractometer (XRD) analysis and Scanning Electronic Microscope (SEM) revealed that the microstructure of RPC was denser using the ternary pozzolanic materials than the original RPC.

• Computers and Concrete
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• 제21권2호
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• pp.167-179
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• 2018

Reactive powder concrete (RPC) is a type of ultra-high strength cement-based material with a dense microstructure, which is made of ultra-fine powders. RPC demonstrate a very brittle behavior, thus adding fibers improves its mechanical properties. In this study, it was attempted to investigate the effect of using steel and polyvinyl alcohol (PVA) fibers as well as their combination on the properties of RPC. In this regard, hooked-end crimped steel fibers together with short PVA fibers were utilized. Steel and PVA fibers were used with the maximum volume fraction of 3% and 0.75%, respectively, and also different combinations of these fibers were used with the maximum volume fraction of 1% in the concrete mixes. In total, 107 concrete specimens were prepared, and the effect of fiber type and volume fraction on the physico-mechanical properties of RPC including compressive strength, tensile strength, modulus of elasticity, density, and failure mode was explored. In addition, the effect of the curing type on the properties of compressive strength, modulus of elasticity, and density of RPC was evaluated. Finally, coefficients for conversion of cubic compressive strength to cylindrical one for the RPC specimens were obtained under the two curing regimes of heat treatment and standard water curing.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2013년도 추계 학술논문 발표대회
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• pp.68-71
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• 2013

Reactive Powder Concrete (RPC) is an ultra high strength and high ductility cement-based composite material and has shown some promise as a new generation concrete in construction field. It is characterized by a silica fume-cement mixture with very low water-binder (w/b) ratio and very dense microstructure, which is formed using various powders such as cement, silica fume and very fine quartz sand (0.15~0.4mm) instead of ordinary coarse aggregate. However, the unit weight of cement in RPC is as high as 900~1,000 kg/㎥ due to the use of very fine sand instead of coarse aggregate, and a large volume of relatively expensive silica fume as a high reactivity pozzolan is also used, which is not produced in Korea and thus must be imported. Since the density of RPC has a heavy weight at 2.5~3.0 g/㎤. In this study, the modified RPC was made by the combination of ternary pozzolanic materials such as blast furnace slag and fly ash, silica fume in order to economically and practically feasible for Korea's situation. The fire resistance and structural behavior of the modified RPC exposed to high temperature were investigated.

• Advances in concrete construction
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• 제11권4호
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• pp.347-356
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• 2021

To address the limitation of the commonly used steam curing of reactive powder concrete (SC-RPC) in engineering, a preparation technology of normal curing reactive powder concrete (NC-RPC) is proposed. In this study, an experimental comparative research on the mechanical properties of NC-RPC and SC-RPC under uniaxial tension is conducted. Under the premise of giving full play to the ultra-high performance of RPC, the paper tries to explore whether normal curing can replace steam curing. The results show that various mechanical indexes of NC-RPC (e.g., tensile strength, ultimate tensile strain, elastic modulus and deformation performance) could basically reach the mechanical index values in steam curing at 28d age, some performance is even better at a longer age. So it affirms the feasibility of normal curing. In this paper, the influence of normal curing age on the tensile properties of RPC is discussed, and the relationship between each index and age is introduced in detail. Based on the experimental data, the tensile mechanism of RPC is analyzed theoretically, and two kinds of tensile constitutive models for RPC are proposed, one is curvilinear model, and another one is polygonal line model. The validity of the two models is further verified by the test results of others.