In this study, experimental research was carried out to evaluate the structural performance of high strength R/C interior beam-column joints regions, with or without the shear reinforcement. Specimens designed by the interior beam-column joint regions without the shear reinforcement of existing reinforced concrete building showed a unstable mode of failure and an decrease in load-carrying capacity and energy dissipation capacity and ductility ratio.

In this study is experiment result of steel fiber reinforced concrete shear walls with deformation capacity and structural performance. To assess the deformation capacity and structural performance of shear walls, slits and steel fiber was used as a variables. The experimental results show that steel fiber reinforced concrete shear wall is superior compared to normal reinforced concrete shear wall. The experimental results of shear wall with slits is too.

In this study, to Assess the Structural performance of Reinforced Concrete Shear Wall with different Slit Length. Variable of analysis is slit length(0, 600, 1200, 1500, 2400mm), showed excellent accuracy. Maximum load is decreased when the slit length increased. But Side sway of maximum load is increased when the slit length increased.

A deterioration of typical reinforced concrete bridge deck is due to the use of calcium chloride, cracks and water penetration inside of the deck slab with steel reinforcement. Therefore, in order to eliminate the defects of reinforced-concrete decks in terms of material, the steel-straped deck system is studied and developed by maximizing the arching effect while the girders are restrained using straps in lateral direction to the bridge. This parametric study was performed to analyze the structural characteristics of steel-straped deck, and to identify the factors of the thickness, span length and lateral restraint stiffness of deck slab considering the concrete nonlinearity.

In this study, it was developed eco-friendly zero cement fiber reinforced concrete using ground granulated blast furnace slag and alkali activator(water glass, sodium hydroxides). Also, it was evaluated the flexure capacity of the RC beams using zero cement concrete. The eco-friendly concrete using zero cement encouraged alkali activation reaction has rapid hardening speed and showed possibility as a high strength concrete. Also, the RC beams applied this showed similar movement and destroy tendency with RC used previous cement.

Fiber reinforced polymer (FRP) reinforcing bars for concrete structure, as a non-corrosive material, has been extensively investigated by many researchers. However, it has not been practically used as the reinforcement or structural material in civil engineering structures due to its low elastic modulus if glass fibers were used. This study was motivated to overcome this shortcoming of FRP bars to be used for concrete structures. Material hybridization was applied to enhance its elastic modulus. The effect of material hybridization was evaluated by comparing the results of tensile test with those of non-hybrid FRP bars.

Since electrical resistivity of concrete can be measured in a more rapid and simple way than chloride diffusivity, it should be primarily regular quality control of the electrical resistivity of concrete which provides the basis for indirect of quality control of chloride diffusivity during concrete construction. This study can provide a non-destructive approach for durability design of marine concrete and it is expected that the result is subsequently used as a calibration curve for an indirect control of the chloride diffusivity based on regular measurements of the electrical resistivity during concrete construction.

The priority order about a rational repair and reinforcement is generally decided by subjective decision of engineer. An appearance investigation carried out to decide about a rational repair and reinforcement through systematic and objective analysis in tunnel. we could prevent expecting leakage through several improvements in the aspects of design, materials and site implementation.

Based on the analysis and test of concrete box structure under blast load, it was found that the blast retrofit by Kevlar/glass hybrid fabric sheet was more effective than retrofit by Carbon fiber reinforced plastic sheet to improve the structural performance of concrete subjected to blast pressure.

The purpose of this study is to suggest standardization solution about non-destructive testing of concrete structures. For this, we analyzed the present condition of non-destructive testing in domestic and based on it, we suggested a draft of standard plan for improvement of reliability and quantitative analysis in the result of non-destructive testing

Image created by stack imaging spectral amplitudes based on the impact-echo (SIBIE) method is largely one-dimensional because a single frequency domain spectrum for wave reflected below a single point of impact is used to create the image. The method has limitations for representing defects in a cross section of a concrete structural element using two-dimensional coordinates. This study focused on defect detection and visualization in a concrete structural element using multiple impacts and accumulated SIBIE. An impactor was used to induce energy at multiple points at positioned at prescribed intervals along the structural element. A modified SIBIE method was applied to the collected data of each point and the modified SIBIE images were accumulated to generate one image (an accumulated SIBIE image).

영도대교는 부산 최초의 연륙교로서 1934년 준공된 이후, 수차례의 보수보강 공사를 거쳤으며 2011년 이후 현재까지 확장 복원을 위하여 철거공사를 실시하고 있다. 본 조사연구의 목적은 영도대교 건설 당시의 교량 기술 및 재료적 특성 분석 함으로써 근대 구조에 사용된 콘크리트의 당시 재료적 특성을 파악하고 근대 교량문화유산의 보존 및 활용을 위한 기초적 자료를 구축하는 데 있다. 일련의 실험을 통하여 콘크리트 구성재료는 시멘트 : 세골재 : 굵은골재 비율이 부위에 따라 1 : 2 : 4 또는 1 : 3 : 6 인 것으로 밝혀졌고, 압축강도는 50~55MPa, 탄성계수는 25~35GPa의 범위로 나타났다. 역학적 물성의 편차가 10%이하인 점을 미뤄봐서 당시의 품질관리가 비교적 우수했던 것을 알 수 있었다. 중성화 깊이는 높은 상대습도로 상당히 낮은 값을 나타내었고, 염소이온 확산계수는 1.052e-12(m2/s)로서 현대 콘크리트와 비교하면 물시멘트비 35%에 상응하는 것으로 밝혀졌다.

이 연구에서는 전단하중을 받는 부유식 콘크리트 구조물 모듈 접합부의 구조거동 실험연구를 수행하였다. 모듈 접합부 전단키의 균열 양상, 전단거동 및 전단강도를 파악하였다. 전단강도의 영향을 파악하기 위해 전단키의 경사각도, 횡방향 구속응력 및 콘크리트의 압축강도 등을 실험변수로 고려하였다. 전단키의 경사각도가 증가함에 따라 접합부의 전단강도가 증가하였다. 또한, 구속응력이 증가함에 따라 전단키의 전단강도가 증가하였다. 실험변수에 따른 전단거동 실험결과를 토대로 접합부의 전단강도 평가식을 제안하였으며, 제안식에 의한 전단강도 예측값은 실험값에 근접하는 것으로 나타났다.

This paper presents design concept as well as trial products to develop hybrid reinforcing polymer bars. The objective of this study is to develop a viable hybrid FRP bar for concrete structures, especially for marine and waterfront concrete structures. Three different types of hybrid FRP bar were considered in the development. Using E-glass fibers, unsaturated polyester resins, and conventional steel bar, hybrid GFRP bar samples of 9 mm and 13 mm in diameter were fabricated as the trial products. The results obtained in the pultrusion process of the trial products are discussed in this paper

In this paper, a finite element analysis to design hybrid reinforcing polymer bars was presented. Two different types of hybrid FRP bar were considered in finite element modeling. To offer the necessity and validity of finite element modeling for the hybrid reinforcing polymer bars, shape and material properties were assumed. Input conditions for analyzing the hybrid reinforcing polymer bars using FEM were verified. Using the results of the finite element analysis, the hybrid reinforcing polymer bars were optimally designed and the results are presented in this paper..

In this study, experimental research was carried out to evaluate the structural performance of the reinforced concrete beam retrofitted by strengthening methods(embedded FRP rod of hexagon, metal fittings) in existing reinforced concrete buildings. Test results showed that the maximum load carrying capacity of retrofitted specimens(BCR, BCR-AC1, BCR-AC2) were increased by 55%, 47%, and 52% respectively in comparison with the standard specimen BSS.

The AEMM uses the ageing factor to consider the effects of the increase of the modulus of elasticity of concrete with time on the deformation and stress distribution of reinforced concrete members. Previous researches proposed appropriate values of the ageing factor when the applied load is constant or the deformation is concstant. In this paper, the validity of ageing factor for the building structures were studied by the comparison with the results of step-by step method