The purpose of this study was to analyze the influence of retarder, fiber and admixture on durability properties of repair mortar mixed MPC(Magnesia phosphate composite). The test results showed that the resistance to freezing-thawing and chloride attack of MPC repair mortar with fibers and fly-ash were greater than those of MPC repair mortar without fibers and fly-ash.

This study aims to establish design and construction procedure in the fields of the repair and rehabilitation for existing concrete structures. The codes used in this study are ISO 16311 and ACI 562-16. The ISO 16311 and ACI 562-16 focused on maintenance and repair, respectively. After, we will make to design and construction guidelines to meet the domestic situation through analysis the repair and rehabilitation parts of the codes in detail.

In this study, the case was analyzed for the repair of the reinforced earth wall during its construction. Such a problem is deemed to require more in-depth design and quality control.

In this study, a case study on the field survey method and repair and reinforcement method of reinforced earth retaining wall damaged by salinity was carried out.

In this study, the case was analyzed for the repair of the reinforced earth wall during its construction. Such a problem is deemed to require more in-depth design and quality control.

Road bridges are affected by de-icing chemicals, which are used to prevent snow and ice on the road. Corrosion of steel girders due to de-icing chemicals are becoming common problems. The deterioration of steel girder ends due to deck joint leakage and occasional spray from passing vehicles usually cause section losses and strength reduction. This report presents th results of a study carried out to repair corroded steel box girder bridge.

Steel corrosion in concrete induced primarily by chloride ingress and its diffusion, deteriorates concrete structures exposed to aggressive agents, such as chloride, significantly. This paper discusses the rehabilitation case study of deteriorated bridge by de-icing salts attack.

In this study, repair and reinforcement priority determining method for each component of existing dams is suggested. Condition assessment results from in-depth inspection followed by “specific guide for in-depth inspection on dams” are used. Condition assessment is subdivided into several steps and evaluation indices are determined by considering weights such as influence coefficients and adjustment factors for each component through all of the steps. These weights are counted backward to determine the priority for each component and facility. An algorithm is designed to analyze this procedure and 4 target dams are adopted to verify the method. This method can be used for establishing an efficient maintenance strategy related to the repair and reinforcement priority determination.

This paper shows examples of damage of sound barrier supports during maintenance. Main causes of damage are wind load, bad construction and maintenance, vibration due to live load, etc. Finally, the measurements for these damaged cases are introduced in the freeway site.

Since deteriorated bridge increases each year in Korea and Japan, the study was conducted for the direction of improving reinforcement and conservation for RC deck t because common facts in damaged RC deck is that crack was found in direction 1 and direction 2 that the crack leads to compound damage.

This case study is evaluation of pier safety for horizontal displacement come from a pile of rock muck under construction, restoration measure and application of repair and reinforcement.

In this study, repair and reinforcement priority of dam facilities was estimated using dam in-depth inspection assessment score and grade. Multi-Criteria Decision Making was used for decision of priority, and assessment scores and weights of individual facilities were applied as payoff matrix and weight coefficient. The results show that different analysis results can be deducted by various MCDM method even if assessment index and weight coefficient are the same.

본 논문은 최근 화물차량 적재물의 충돌로 인해 고속도로상 강박스거더교 하부에 발생한 손상 현황과 손상 부위별로 제안된 보수‧보강 방안을 살펴보고자 한다.

Highway construction to the reinforced earth retaining wall which is under constant traffic load there is a possibility of generating the displacement at the top. In this study, it was conducted determine how to repair reinforcement method through examination of cause and stability analysis when occurs the displacement of reinforced earth retaining wall.

When processing with wood floor covering on wet ondol floor, there are frequent defects caused by floor condensation, floor loosening, lowering of adhesiveness, wood contraction and swelling. The working method is still conventional with problems of lower indoor heating efficiency. Accordingly, ordinary wood floor covering is too expensive without any special functions or features, and it is necessary to suggest reasonable solutions or methods.

신축공사의 비용에 대한 부담과 건설된 지 오래되어 노후화가 진행된 철근콘크리트 구조물의 증가로 유지관리의 필요성이 크게 증가하여 점차적으로 보수⋅보강 분야가 확대되고 있다. 이러한 필요성의 증가로 인해 새로운 보수⋅보강 기술이 국내⋅외에서 지속적으로 연구되고 있다. 국내에서는 철근콘크리트 구조물의 보수⋅보강공법으로 강판접착공법, 섬유보강 (Fiber reinforced plastic, 이하 FRP) 표면부착공법, 외부 프리스트레싱공법 등이 사용되고 있다. 이러한 방법 외 Steel mesh로 보강한 시멘트 모르타르 (Steel Mesh Cement Mortar;SMCM)을 이용한 보수방법을 고려하고자, Steel mesh 의 보강 면적, 그리고 보강 층 수 (number of layer)를 달리하여, 3점 휨 부재 실험을 수행하였다. 1400×500×200 (mm)의 기본 철근 콘크리트 (RC)를 포함하여 총 5종류의 시편을 제작하였으며, 처짐량을 측정하기 위해, 시편 상부에LVDT를 설치하였으며, 시편 중앙부에 철근 변형률 게이지와 콘크리트 변형률 게이지, 전단 철근에 철근 변형률 게이지를 부착하였다. 3점 휨 실험 결과, 모든 하중-변위 곡선에서 공통적으로 SMCM으로 보강한 시편이 기본 RC에 비해 최대하중이 더 높은 것을 확인할수 있었다. SMCM을 두 층, 그리고 기본 RC 하부 전체에 보강을 할 경우, 기본 RC에 비해 최대 하중은 1.18배, 처짐은 최대 1.37배 더높은 것을 확인할 수 있었다. 시편의 종류마다 조금씩 다른 양상을 보였는데, 이는 SMCM과 RC의 부착 정도의 차이로 인해 결과의 차이가 발생한 것으로 보인다.특히, 지점부 안쪽으로 부분 보강하고, Steel Mesh를 한 겹으로 보강한 네 번째 경우 (SM-B1)에는, SMCM이 실험 도중 박락되는 현상이 발생하였다. SMCM을 보수⋅보강 재료로서 활용하기 위해선 RC와의 부착 성능 향상이 필요하다고 판단된다.

In this paper, the maintenance characteristics for the abutment and pier in highway bridges are investigated. The repair and rehabilitation properties are integrated from the Highway Bridge Maintenance System until 2013. Whole numbers of the abutment and the pier in highway bridges are over 37,000. The repair and/or rehabilitation are carried out for the substructure of about 10,240. More than 35 billion won of budget for repair and rehabilitation were used until now. It can be known that during one year about 37,000 won of budget has been used to maintain and preserve each substructure.