Recently there are many study on the effect of improving the compressive strength of MWCNT-cement composites. However study related to MWCNT-cement yet insignificant to the domestic. The MWCNT have excellent mechanical characteristics which are mixing cement. MWCNT-cement composites can be expected improving compressive strength. This parametric experimental study have verified to increasing compressive strength of mortar composites mixing MWCNT as W/C, curing age.

This study was aimed to investigate the difference in strength of Carbon Nanotube (CNT) reinforced cement mortars with different types of surfactants and doses. In the experimental program, CTAB, SDBS and TX10 which were common surfactants adopted to improve CNTs dispersion in fabricating CNT composites in many industrial fields were included and superplasticizer which was revealed to be effective to disperse CNTs especially in CNT reinforced cementitious composites were added as well. Superplasticizer presented less strength reduction in cement mortar and more strength gain by adding CNTs among four types of surfactants. Higher dosage of superplasticizer caused lower strength of cement mortar. Adding CNTs of 0.4 wt.% or less to cement didn’t show strength enhancement by adding CNTs but 0.8 wt.% of CNTs resulted in strengthening effect after all. Finally, a combination of 0.1 wt.% of CNTs, superplasticizer and sonication treatment could lead to strength improvement by adding CNTs in cement mortar.

In this study, we intended to estimate the heat of hydration of carbon nanotubes-cement composites. It was tried to present the basic data of the heat of hydration characteristics of the CNT-reinforced cement composite by the simple adiabatic temperature rise test. The results indicated that adding CNT reduced the heat of hydration of cement composites.

This study was intended to estimate the effect of adding CNTs into cement paste on the rheological properties. it was found that higher content of CNTs increase yield stress but there was no noticeable correlation between CNTs dosage and plastic viscosity.

In this study, impact of high-velocity projectile by mixing steel fiber, polyamide, nylon, polyethylene fiber which have different shape and properties respectively. Scabbing is restrained because of micro-crack caused by the shock wave offset effect and energy dispersive of synthetic fibers are mixed populations.

In this study, AC/DC responses of CNT-filled cement composites are measured and compared. Based on the results, it is found that AC measurement method is more reliable to measure the electrical resistance of CNT-filled cement composites.

In this study, an equivalent circuit model of CNT-filled cement composites is proposed. Both the polarization effect of electrode/composite interface and the complex resistance effect due to dielectric property of CNT cement composite are considered in the proposed model. Effective of the proposed model will be experimentally validated.

This experimental study investigates the influence on the tensile behavior of strain-hardening cement composite (SHCC) with HR and SWP Shrinkage Reducing Admixture (SRA). SRA can also improve the tensile strength and multiple cracks of SHCC material used in this study.

This experimental study investigates the influence on the flexural behavior of strain-hardening cement composite (SHCC) with HR and SWP Shrinkage Reducing Admixture (SRA). SRA can also improve flexural strengths and flexural toughness.

In this research, it is shown a nonlinear analysis of reinforced concrete (RC) composite columns by applying high-performance fiber-reinforced cementitious composite(HPFC) mortar. The developed model was considering the high-ductile characteristic of HPFC mortar. In the result, the analysis by the model was well predicted the experimental behaviors the RC composite column.

This paper describes the flexural performance of concrete and strain-hardening cement based composite (SHCC) beams reinforced with normal and high-strength steel bar to evaluate the effect of reinforcing bar strength and cement composite type. The present investigation shows the potential of high-strength structure materials used of high-strength reinforcing bars with SHCC. And superior mitigation of crack-damage is observed reinforced SHCC beams than reinforced concrete beams

This experimental study examines the test results on the flexural behavior of strain-hardening cement composite (SHCC) with two types of Shrinkage Reducing Admixture (SRA). An influence of SRA on the flexural behaviors of SHCC mixes was observed.

Cementitious material is widely used as a consturction material but they have a quasi-brittle behavior and low tensile strength. We tried to use CNT as a filler for improving such a problem. For achieving good dispersion of CNT, superplasticizer was used as a dispersion agent and sonication process was appiled.

실제 교량의 바닥판에 적용할 목적으로 섬유의 길이 및 혼입량을 달리한 두 가지 초고성능 시멘트 복합체를 고려하고 있다. 이 연구의 목적은 이 두 재료의 균열저항성을 평가하는 것이다. 두 재료에 대한 휨인장 파괴실험을 수행하였고, 실험으로부터 얻은 하중-균열개구변위 관계를 최적으로 모사하는 인장응력-균열개구 관계를 역해석을 통해 파악하였다. 역해석결과 13 mm 길이의 섬유를 2% 함유한 UHPCC는 16.3 mm와 19.5 mm 길이의 섬유를 각각 0.5%와 1.0% 함유한 UHPCC에 비해 파괴에너지가 작은 것으로 나타났다. 균열을 보다 분산시키고 균열폭을 감소시키기 위해서는 길이가 긴 두 종류의 섬유를 혼용한 UHPCC를 사용하는 것이 바람직할 것으로 판단된다.

Waste stone sludge generated during the collection of crushed aggregate is difficult to use due to high moisture content. Production of 1 ton aggregate generates approximately 0.25 tons of waste stone sludge. Considering the total crushed aggregate collection in 2012 of about 100 million tons, it can be estimated that 25 million tons of waste stone sludge is generated annually. Recycling of waste stone sludge is made difficult by the high moisture content of 30%. Therefore, to make recycling this process must be a drying process, which makes a fine powder of even better quality that can use as an additive. The purpose of this study is to analyze the changes in physical properties caused by the use of dried waste stone sludge as an additive in the extrusion of cement. A test specimen was made, substituting 50% of the silica with waste stone sludge, and physical performance evaluation was performed. Results showed that 50% substitution of silica resulted in no difference in moldability, but a slight increase in the water content required for the same workability was found. Flexural strength and drying shrinkage were found to be 97% of normal levels, but satisfied the specified performance in the KS F 4735 standard.

In spite of advantages of the use of CNT, one of the largest obstacles to improve strength of CNT composites is the difficulty of getting a good dispersion of the carbon nanomaterials in a matrix. We tried to mix CNT composites with some of surfactant for getting a good dispersion and compared the results of compressive strength test.

Strain Hardening Cement-based Composites(SHCCs) are attractive materials for energy dissipation and crack damage mitigation. This study investigated the flexural performance of SHCC beams layered Strain-Hardening Cement-based Composite(SHCC). The flexural behavior of RC beams carried out four-point loading test. Test results indicated that PE30_20 compared with Con30 initial cracking load, the stiffness, the yielding strength was higher.

This paper presents the results of a study performed to evaluate uniaxial tensile performance and obtain a better understanding of the behavior of SHCC using an expansive admixture. To evaluate a performance of SHCC using an expansive admixture was tested a compressive strength, flexural strength, and uniaxial tensile strength.

The objective of this study is to investigate the failure modes of steel coupling beam-wall connection. Test variable of this study is types of material used, concrete and with pseudo strain hardening cementitious composites (PSH2C). The results showed that Specimen PSH2C-SB with longer embedment length of steel coupling beam exhibits good seismic performance than Specimen HCWS-SB.

변형경화형 시멘트 복합체(SHCC)는 직접인장 상황에서 FRCCs에 비해 우수한 변형경화 특성을 갖는 재료이다. 하지만 SHCC는 일반적인 콘크리트에 비해서 시멘트비율이 높은 부배합 이며, 이에 따라서 자기수축이 큰 특성을 갖는 재료이다. 따라서 시멘트 복합체 내에 팽창재를 대체함으로써 수축저감을 통한 성능향상을 기대하였다. 이 연구에서는 각 강도별 SHCC의 배합에 팽창재를 대체함에 따른 역학적특성을 평가하고자 하였다. 시험결과 설계기준 압축강도 70MPa 배합이 압축, 인장, 휨, 시험에서 우수한 역학적 특성을 나타내었으며, 균열 특성에서는 팽창재를 대체한 SHCC가 균열분산 및 연성에서 우수한 특성을 나타내었다.