In this study, the chloride ion diffusion coefficient of ECC coated with silane-based protecting materials were evaluated. The evaluation was carried out according to NT BUILD 492. The test results show that when the protective material is applied to ECC, the chloride diffusion coefficient is reduced by 40-50%.

In this study, the setting times of mortar using the biopolymer in seaweed was evaluated by penetration resistance. The evaluation was based on the method presented in KS F 2436. Test results show that the biopolymer was used instead of the synthetic polymer, the termination time was delayed.

In this study, presents the mechanical bond strength properties of mortar using bio polymer in seaweed. The evaluation was based on the method presented in KS F 2762. It was confirmed that the resistance performance all levels of biopolymer using mortar excellent performance with bond strength over 1.0 MPa as defined in KS F 4042 『Polymer-cement mortar for Concrete Structures』.

The purpose of this study is to use organisms or micro-organism functions for eco-friendly water-purification according to concentration in porous concrete using EM, utilizing bioremediation.

This paper presents the mechanical properties of high performance fiber-reinforced concrete composites(HFCC) according to binder replacement rate. the compressive strength and single-axial tensile strength of HFCC were evaluated according to binder replacement rete. As a result of the test, the compression strength decreased as binder replacement rates increased, and B-20 mix properties expressed the most ideal tensile strain-stress curve.

In this study, the absorption protection agent was applied to the surface of fiber reinforced concrete to evaluate the chloride ion penetration resistance. The evaluation was based on the method presented in KS F 2711. It was confirmed that the resistance performance against chloride ion was improved by 56∼71% when the coating material was applied.

Recently, the demand for large diameter piles has been rapidly increased in order to secure the allowable bearing capacity of pile foundation due to the increase of large structures such as high rise buildings. In this study, to improve the shear capacity of a conventional PHC pile, a large diameter composite PHC pile strengthened by in-filled concrete and shear reinforcement was manufactured. All the piles were tested according to the shear strength test method of Korean Standard. As a result of the shear test, the F-type piles which are produced without shear reinforcement occurred abrupt horizontal cracks after flexural and inclined shear cracks occurred. On the contrary, the FT-type piles which are produced with shear reinforcement exhibited stable flexural and inclined shear cracks uniformly over the entire pile without abrupt horizontal cracks. Furthermore, the maximum load of the large diameter composite PHC pile improved to 2.9 times in the F series, and more than 3.3 times in the FT series compared to the conventional PHC pile. This result indicated that FT-type piles had excellent composite behavior due to the shear reinforcement and effectively prevented the unstable growth of inclined shear cracks.

The purpose of this study is to use crushed gravel for eco-friendly water-purification according to concentration in porous concrete.

최근 제설제의 영향으로 콘크리트에는 복합열화가 작용되어 도로시설물에 대한 2차 피해와 유지 보수 비용이 급격히 증가되고 있다. 그래서 실란, 실록산 계열의 흡수방지제를 사용하여 콘크리트 내부로 침투되는 수분 및 염화이온을 차단하는데 이용하고 있는 실정이다. 본 연구에서는 실란, 폴리실록산 계열의 흡수방지제가 갖는 단점을 개선하고자 이를 구형으로 제 조하여 콘크리트 강도별 침투깊이 및 동결융해저항 성능을 분석하였다.

In this study, cement mortar (KS F4041) used for surface of floor was evaluated for durability of abrasion according to the mixing ratio of polymer. From the experimental results, it was confirmed that as the polymer content increases, the durability of abrasion properties increase.

The vegetation-based spraying method has been used as a revegetation measure for protecting slopes. However, after the method is applied to the fields, the collapse due to deteriorated bond performance of artificial slopes and defective vegetation growth bases prevent it from displaying its proper function. Therefore, research and application technologies for revegetation measures that can achieve both the reinforcement of slopes and the ecological restoration at the same time are necessary. Accordingly, in this study, fundamental research was conducted regarding the bond properties of slopes, according to the addition of additives based on bonding materials for improving bond performance.

In this study, dry shrinkage was evaluated by adding limestone powder according to the substitution ratio to Engineered Cementitious Composite. The test method was carried out by KS F 2424, and it was confirmed that the drying shrinkage tends to increase slightly as the substitution ratio of the limestone fine powder increases.

최근 유통·물류 산업의 발달로 산업용 창고 바닥의 중요성a이 점점 높아지고 있다. 본 연구에서는 기존의 바닥재료로 사용되어 온 일반 시멘트계 모르타르가 가지고 있는 유동성의 한계 및 긴 양생 시간 등의 단점을 보완할 수 있는 속경성 폴리머 모르타르 바닥소재를 개발하 였다. 속경성 확보를 위해 초속경 시멘트를 결합재로 사용하였고, VAE 폴리머 분말수지를 5%~20% 혼입 범위로 설정한 4종류의 배합과 혼입 하지 않은 Proto배합에 대한 기초물성을 유동성실험, 압축강도실험, 휨강도실험, 부착강도실험 및 마모실험을 통해 평가하였다. 유동성 실험 결과를 통해 고성능 감수제량를 조절함으로써 플로우 250 mm 이상의 고유동 특성을 확보할 수 있었다. VAE 폴리머 혼입은 압축강도 감소에 영향을 미치는 것으로 나타났지만 휨강도는 Proto배합에 비해 우수하게 증진시킬 수 있어 압축강도/휨강도비를 증가시키는 것으로 평가되었 다. 또한 최소 2.6배 이상의 부착강도 향상과 4배 이상의 마모저항성을 확보할 수 있었다. 역학적 실험을 통해 VAE 폴리머 최적 혼입률을 10% 로 결정하였고, 현장적용 및 모니터링을 수행한 결과 VAE 폴리머를 혼입하지 않은 바닥재에 비해 오염도, 충격에 의한 저항, 부착성능 등이 우 수한 것으로 나타났다.

The purpose of this study was to evaluate flowability of engineered cemetitious composite(ECC) Using blast furnace slag and fly ash as a binder in mixture. From the test result, flowability value of all ECC mixtures show good flowability and self compacting performance.

From the test results, it was found that the compressive strength and the resistance of chloride ion penetration were evaluated the slag content of the concrete for bridge pavement. Compressive strength test results showed that initial strength was decreased as slag replacement ratio increased. The chlorine ion penetration performance increased with increasing strength.

In this study, cement mortar (KS F 4042) used for repairing concrete structures was evaluated for compressive strength and bond strength according to the mixing ratio of polymer. From the experimental results, it was confirmed that as the polymer content increases, the bond strength properties increase, but the compressive strength decreases slightly at a certain rate.

Phase change material (PCM) has been developed and applied in various fields as construction material. If the application of PCM as the semi-rigid pavement cement grout becomes available, it would be possible to control the occurrence of a micro crack due to the generation of hydration heat in the ultra rapid harding cement, and if the occurrence of a micro crack is reduced, it would be possible to improve the cohesion performance between asphalt matrix and grout as well as to compact the matrix of the pavement material, improving the durability. Therefore, the applicability review of PCM for the purpose of improving the semi-rigid pavement materials through the shrink reduction of ultra rapid harding cement used as the semi-rigid pavement cement grout was carried out in this study.

In this current study evaluated the horizontal shear strength of reinforced concrete pile between pile body and infilled concrete interface. From the calculated results of horizontal shear strength it was found that the interface between pile body and infilled concrete was evaluated to be able to safely resist factored shear stress.

In This study, the bio-inspired high energy absorption cementitious composites was developed which is a new structural material performing a high energy absorption and ductility property imitated from shells. The flexural performance of the cementitious composites was evaluated and as a result, excellent ductility was obtained.

Due to the economic growth and development of construction technology, a role of foundation to resist heavy loads has been increased. In this present study to improve the structural performance of reinforced concrete pile, the precast HPC pile reinforced with rebar and filling concrete was developed and the strength of pile was predicted based on the limit state design method. The safety of HPC pile strength was evaluated by comparing with the design values. The geometry of HPC pile is a decagon cross section with a maximum width of 500 mm and a minimum width of 475 mm, and the hollow head of pile thickness is 70 mm. The inner area of the hollow head part was made as the square ribbed shape presented in the limit state design code in order to achieve horizontal shear strength between pile concrete and filling concrete. From the shear test results, it was found that the stable shear strength were secured without abrupt failure until maximum load stage despite the shear cracks was found. Shear strength is 135% and 119% higher than that of design value calculated from limit state design code. The driving test results of HPC pile according to the presence of additional reinforcement showed the outstanding crack resistance against impact loads condition. From the bending test results the flexural load between PHC pile and HPC pile was 1.51 times and 1.48 times higher than that of the design flexural load of conventional PHC pile.