The purpose of this study is to investigate the causes of corrosion of steel plate deck longitudinal U-ribs and to investigate the reinforcement method. It was confirmed that the corrosion of the longitudinal U-ribs occurred due to penetration water of the bolt hole of the shear key used in construction. The longitudinal U-ribs which were corroded were stiffened by attaching reinforcing plates, and finishing treatment was performed to prevent the surface water from flowing into the inside.

In this paper, the flexural behavior of RC member recycled heavy weight waste glass as fine aggregate was evaluated by finite element analysis. From the results, yield point and maximum load decreased with decreasing concrete strength and elastic modulus. Also, the finite element analysis program does not reflect the ductility loss of RC members using heavy weight waste glass as fine aggregate.

When estimate Short Lenth External Tendon's tension by Vibration Measurement Method, We Consider Tendon's Boundary. This paper is a case about estimation of short lenth tendon's tension by using practical formula estimation and stiff string with clamped-clamped boundary conditions.

In this paper, the heavy metal leaching of mortar substituted the crushed waste glass as fine aggregate are evaluated. From the results, when the heavy weight waste glass substitution ratio increase, leching quantities of heavy metal is increased. Therefore, it is needed that the characteristics of heavy metal leching according to waste glass substitution ratio in mortar specimens.

In this study, chloride penetration of calcium leached concrete according to mineral admixture ratio were compared with OPC. From the results, it showed that chloride diffusion coefficient in calcium leached concrete were increased as calcium leaching period increase. However, the chloride diffusion coefficient of BFS case showed the better resistance than Fly Ash case. And, the distribution of chloride diffusion coefficient was significantly changed by calcium leaching period.

Vibration measurement analysis and In-depth inspection were carried out to understand the cause of defects occurred on joint of bridge. A cause of defects, such as metallic sounds, water leak&corrosion and rubber seal rupture turn out to be due to deterioration and vibrating impact by period so that the bridge is in need of repair and effective maintenance.

The objective of this study introduce improperly welded Vertical stiffner. Function of vertical stiffner is prevent buckling of web pannel. If Vertical stiffner have some defect, it Should be reviewed structural perspective. And Avoid immediate repair through structural review.

The purpose of this study is to measure the abnormal behavior of the bridge with LRB and to analyze the cause. Based on the result of analysis, the abnormal behavior was mainly due to the absence of pre-set process during replacement and the integrated behavior due to constriction of adjacent RAMP.

본 연구에서는 초기 균열을 도입한 철근콘크리트 부재에 대한 침지 염화물 침투 실험을 수행하였다. 염화물 확산 특성과 임계 균열폭을 비교하였으며, 콘크리트 자기복원 특성을 검토하였다. 실험결과에 따르면, 표면 균열폭이 증가할수록 염화물 침투저항성이 크게 감소하였으며, 광물질 혼화재를 사용할 경우, 비균열 부재의 염화물 침투저항성은 크게 개선되었지만, 고로슬래그 및 플라이애쉬 혼화재를 사용할 경우에 균열이 발생하게 되면 도리어 염화물 침투저항성은 보통 콘크리트에 비해 크게 저하하였다. 임계 균열폭은 침지 염화물 침투 실험 결과 평균 29㎛으로 측정되었다. 자기복원 현상에 의해 4∼15㎛범위의 균열이 복원되었다. 그러나 콘크리트 자기복원 현상에 의해 시각적으로 복원된 부분의 염화물 침투 저항성은 완전히 회복되지 않았다.