In order to measure the rheological behavior of precast concrete with high volume of recycled fine aggregate, the replacement of natural fine aggregate by recycled one was carried out in dry-mix process. As results of that, it was found that as the replacement increases, strength and performance of concrete become decreased but may be recoverable by proper selection and dosage of constituents.
This paper describes the influence of recycled materials on the flowability of steel fiber-reinforced cement composites. For the FRCC, fly-ash and recycled sand were used as recycled materials. The recycled materials were mixed with replacement ratios of 25% and 50%. As reinforcing fiber for the FRCC, micro steel fibers were used. Based on the test results, flowability of FRCC was improved when fly-ash was replaced. Increase of recycled sand had FRCCs exhibited lower flowability.
This paper introduces the recent development of GFRP-steel hybridized rebar and deals with an evaluation of its mechanical performance by authors. The objective of this study is to investigate tensile and bonding performance of the GFRP-steel hybridized rebar. The effect of hybridization on tensile properties was evaluated by comparing the results of tensile test with those of non-hybrid GFRP bars. The surface of the bar was designed and experimentally evaluated to obtain the sufficient bond strength in this study. To ensure the long-term durability of GFRP-steel hybridized rebar to corrosion resistance, the individual and combined effects of environmental conditions are currently under investigation.
In this study, the recycling water that produced during remicon manufacturing was activated by desulfurization gypsum, and then mortar with activated-sludge was made. As a result, possibility of activated-sludge in remicon was verified via flow and compressive strength test.
In this study, industrial by-products such as desulfurization gypsum and C12A7-based slag was used for activating recycling water. Consequently, it was verified via test that workability and compressive strength were not affected on activated-sludge.
as subsea tunnel support. As a result, the shotcrete mixture with slag is excellent evaluated in terms of flexural strength compared with existing shotcrete.
Based on the study of strength development characteristics of Ground granulated blast-furnace slag(GGBFS), it was found that the use of GGBFS as a admixture was advantageous in terms of long-term strength. Therefore, GGBFS can be a replacement for the Flyash which is currently used in the NPP.
Recently, a Multi-Walled Carbon Nano Tube(MWCNT) is widely used to increase mechanical strength of the cementitious composite material. In this study, a dilution of MWCNT aqueous solution(from wt 2.0%, 1.5% to wt 1.0%) is a main parameter. A compressive strength of diluted CNT cement mortar is maximum 4.7% larger than that of a pure CNT cement mortar. The result indicates that the diluted MWCNT aqueous solution of the MWCNT cement mortar makes very little differences of the compressive strength.
The study is aims at determining mechanical properties of pva fibers reinforced cement composite with recycled materials to overcome problems of plain concrete. The cement composites were evaluated using different ratio of recycled materials
In this study, mock-up test of ternary blended concrete using structure was conducted in order to evaluate the temperature rise. The results of the mock-up test, it was found that it was convenient to obtain the minimum temperature rise of 3:5:2 mixing.
In this paper, the tensile stiffness and deformation of laminated rubber bearing is investigated based on the research and test results. ISO 22762 and JIS K 6410 are not providing the tensile characteristics of rubber bearings. Besides, the tensile stiffness and deformation models are proposed by several researchers by quite different methods. Proper models are recommended for nonlinear deformation state in order to propose the tensile model and build up base data.
SIFCON's mechanical properties were investigated experimently to develop for anchor block. A normal concrete was used to compare with SIFCON. As a result, SIFCON has higher strength and toughness those of normal concrete.
In this paper, the material characteristics of green slope soil for application to vegetation shotcrete using mineral additive are evaluated. From the results, when the compaction level increase, soil hardness and soil strength are increased. However, the cohesion and angle of internal friction are not significantly affected by mix proportions.
This paper presents an experimental study on the improvement of ductile and flexural strength for high performance fiber reinforced cementitous composites (HPFRCC). The test was evaluated by compressive and flexural behavior of HPFRCC(compressive strength : 180 MPa) according to aspect ratio and volume contents of steel fiber. The flexural strength was increased by aspect ratio near 100 or increasing volume contents of steel fiber while there is no clearly result on the compressive strength.
Even though high performance concrete was developed according to becoming bigger and higher of reinforced concrete building, the rheological evaluation is not enough to use as input data to accomplish the numerical analysis of construction design. Consistency curves were measured by the viscometer as hydration reaction time passed. There are a sudden change of viscosity and yield stress around initial setting in case of low W/B. The increase of workability by the change of free water in cement paste was offset by the coating effect of impermeable layer in case of W/B 40%.
This study was evaluated compressive strength of fiber reinforcement mortar using basalt fiber as part of a basic study for development to fiber reinforcement mortar using basalt fiber. Results of assessment, influence of the compressive strength according to used superplasticizer (SP) has shown that without, in addition, compressive strength according to used viscosity agent (VA) is determined that the compression strength decreased due to the bubbling.
The mechanical properties of high temperature mortar reinforced by polypropylene fibers were investigated in this paper. Ordinary portland cement was used as basic binder and the effect of the replacement of fly ash, slag, silica fume and graphite for Ordinary portland cement was investigated.
The purpose of this study is to investigate correation between semi-adiabatic temperature and adiabatic temperature rise of ordinary portland cement(OPC) and ternary blended cement(TBC). And concrete adiabatic temperature rise factor was estimated by semi-hydration heat analysis test.
This research intends to develop a photocatalytic concrete enabling to decompose the nitrogen oxides (NOx) using a titanium oxide photocatalyst for reducing the cost. In details, this research develops the mix composition of the photocatalytic concrete exhibiting photolytic characteristics and establish the technology enabling to reduce the emission of air pollutant caused by nitrogen oxides.
Concrete behaves as a brittle material with low tensile strain capacity. By adding fibers, the cracking in concrete matrix is controlled, and the mechanical properties are improved. In this study, the mechanical properties of fiber reinforced concrete are compared with fiber type and fiber volume fraction. From the results, the fiber mixed in concrete must be at least 0.5% regardless fiber type, in order to ensure the compressive and flexural strength equivalent or higher than OPC.