Recently, the increased maintenance cost of underground structures due to leakage problems. Also, social issues are discussed in the sink hole caused by the loss of groundwater. For this reason, Leak diagnosis, waterproof and repair of underground structure is important today. So, the aim of this study was the necessity for water leak diagnosis and repair of underground structures.

This study examines the compressive strength of cementless mortar in order to evaluate its mechanical characteristics according to the admixing of fly ash and blast furnace slag. This result showed that cementless mortar for shotcrete repair materials is profitable for using ZrSF.

In this study, analyze the proper repair works and after repair works before it, such as via the structural analysis and investigation of various site of damaged of suspension bridge due to the collision of the vehicle is an accident artificial, make sure those good analysis result has been.

In this study, the rahmen bridge damaged by the chloride attack was investigated. According to the investigation, the degraded concretes on cantilever kerb and end part were intensively observed. Thus, the chloride content test and half-cell method were performed to evaluate the degraded parts. As a result, the contents of chloride on degraded parts were C and D grade. On the other hand, the half-cell potential values of rebar in degraded concrete were measured with the minor corrosion. Thus, the freeze-thawing action due to deicing water is more influential than the expansion of rebar corrosion by chloride attack. Consequently, the economical repairs of degraded parts is more favorable than the replacement of the degraded parts. Also, it is necessary to inhibit the corrosion of rebar in concrete.

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.

The goal of this study is to investigate an evaluated aerial work flatform for structure maintenance and repair. This study includes technical components and economic aspect. The investigation is extend and helpful to accomplish successful business according to foreign and domestic business.

Reinforced concrete structures are deteriorated in a few decades due to various causes, such as carbonation. Therefore it is important to evaluate the accurate carbonation depth in order to secure the durability of the structure. In this paper, carbonation depth by drilling excavation and splitting core sample are compared. Also, the procedure for estimating the appropriate repair zone is proposed, with the result of carbonation depth and steel bar detection.

Structure analysis and field instrumentation were carried out to understand the cause of crack taken place on a cover plate of a lower flange in plate-girder bridge. A cause of the crack turn out to be fatigue stress so that the bridge is in need of repair and reinforcement such as surface grinding, rewelding after gouging and reinforcement for a part of welding on a cover plate.

본 논문은 경상남도 합천군 황매산 법연사 일대에서 2012년 9월 중순 태풍“산바”에 따른 집중호우에 의해 발생한 산사태의 현황조사 결과를 소개하고 이에 대한 안정성을 검토하여 영구적인 보강대책을 제시한 내용을 소개하고자 한다.

본 논문은 2011년 8월초 태풍“무이파”에 의한 영향으로 경상남도 하동군 일대에 발생한 집중호우로 고소성 주변 일대에 발생한 비탈면 붕괴, 옹벽붕괴 및 배부름, 배수로 파괴 등 현황조사 결과를 소개하고 이에 대한 안정성을 검토하여 영구적인 보강대책을 수립한 내용을 소개하고자 한다.

아스팔트 콘크리트 포장 파손 중 40cm-50cm 지름과 5cm-10cm 깊이를 갖는 움푹 파이는 형태의 포장 파손을 포트홀(pothole)이라고 한다. 포트홀 파손 발생 메커니즘은 아스팔트 혼합물에 수분이 침투하고, 아스팔트 바인더와 골재의 점착력이 침투한 수분에 의하여 약화되어 발생한다. 따라서 아스팔트 콘크리트 포장의 포트홀은 주로 장마 기간에 많이 발생하지만 최근 들어 지구 온난화의 영향으로 겨울철 강우 또는 강설의 증가와 제설제의 영향으로 겨울과 봄에도 많이 발생하고 있다. 본 연구에서는 아스팔트 콘크리트 포장에 발생한 포트홀 파손을 효율적으로 상온에서 보수할 수 있는 보수 재료에 대하여 25℃에서 간접인장강도시험을 수행하고, 5회 동결융해 반복 후 간접인장강도시험을 수행하여 인장강도비(TSR, Tensile Strength Ratio)를 산정하였다. 이때 사용된 우레탄 개질 아스팔트 포트홀 보수재는 목표 공극률 4%대의 혼합물을 사용하였으며, 비교대상 상온 보수재는 사전 혼합된 형태로 사용되고 있는 기성 제품 2종류를 선정하였다. 각각의 포트홀 보수재는 양면 50회 다짐을 수행하여 공시체를 제작하였다. 동결융해 조건은 KS F 2398에 따라서 영하 18℃에서 16시간 방치한 후 60℃ 항온수조에서 24시간 담그는 것을 동결융해 1회로 보고 5회 반복한 후 간접인장강도시험을 수행하였다. 5회 동결융해 반복시험 후 인장강도비가 우레탄 개질 아스팔트 포트홀 보수재의 경우 35%이며, 비교 대상 상온 포트홀 보수재는 각각 67%와 66%로 나타났다. 우레탄 개질 아스팔트 보수재의 인장강도비가 다른 두 혼합물보다 50%정도 인장강도비가 작은 것으로 나타났지만 5회 동결융해 반복 시험 후 25℃의 인장강도값의 경우 비교 대상인 상온포트홀 보수재가 개발중인 상온 포트홀 보수재보다 각각 36%와 12%로 매우 작은 것으로 나타났다.

태풍, 호우등 자연재해로 인한 사회기반시설물 피해를 예방하고 저감시키기 위한 예방 차원의 연구는 다각도로 수행되고 있는 반면, 대응 및 응급복구를 향상시키기 위한 연구는 미비한 실정이다. 본 논문에서는 효율적이고 신속한 피해복구를 지원하고자 피해복구 의사결정 지원시스템의 개발방안에 관한 연구를 수행하였다. 피해복구 의사결정 지원시스템은 복구자원 관리, 복구 우선순위도출, 피해복구 종합계획 수립 및 복구 지원 요청의 세부 모듈로 이루어져 있다. 복구자원관리 부분은 여러 개의 DB 엔티티로 구성되어 있으며, 복구에 필요한 모든 자원을 포함한다. 복구자원(인력 및 장비)은 복구공법과 연계되어 피해복구 종합계획 수립에 사용되며, 복구자원관리 모듈을 통해 효율적으로 관리할 수 있도록 설계하였다. 그와 더불어, 시스템 아키텍처, 복구자원 현행화 방안, ODATA 활용, DB설계, Map을 이용한 자원 정보 표출, 그리고 복구계획 및 실시에 대한 개념설계를 수행하였다. 본 연구는 사회기반시설물에 재해가 발생했을 때 보다 신속하게 복구하여, 2차 피해확산을 방지하고, 인명 및 재산 피해를 최소화 하는데 적용될 수 있을 것으로 판단된다.

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.

In recent years, many potholes in asphalt pavement occurred. In order to facilitate the repair, in this study, repair materials with high durability and excellent productivity appropriate for asphalt pre-cast materials was developed. Physical properties test and durability test of various repair materials(SMA, PMA, guss mixtures, water-reactive mixtures) were performed. In order to evaluate the workability at pre-production time of samples using repair materials were made in different shapes and sizes. Finally, after comparing mixtures, water-reactive mixture was selected as repair material. This was verified through several testing.

Hepatocytes derived from human embryonic stem cells (hESCs) may be a useful source for the treatment of diseased or injured liver. However, a low survival rate of grafted hepatocytes and immune rejection are still major obstacles to be overcome. We previously showed that secreted proteins (secretome) from hESC-derived hepatocytes had a potential therapeutic power in the tissue repair of injured liver without cell transplantation. The purpose of the present study was to discover key protein(s) in the secretome of hESC-derived hepatocytes using proteomic analysis and to study the tissue repair mechanism which may be operated by the secretomes. Purified indocyanine green+ hepatocytes derived from hESCs displayed multiple hepatic features, including expression of hepatic genes, production of albumin, and glycogen accumulation. The nano-LC/ESI-QTOF-MS analysis identified 365 proteins in the secretome of hESC-derived hepatocytes and the protein functional network analysis was conducted using the MetaCore TM from GeneGO. In addition, 20 tissue regeneration-related transcription factors (TFs) were extrapolated through further proteomic analysis. After intraperitoneal injection, the secretome significantly promoted the liver regeneration in a mouse model of acute liver injury. Protein functional network analysis on the secretome-induced regenerating liver confirmed 20 transcription factors (TFs) which were identified in the ICGhigh cells. The upreguation of these tissue repair-related TFs were validated by qPCR and western blotting on the regenerating liver tissues. These results demonstrate that application of the secretome analysis in combination with the protein functional network mapping would provide a reliable tool to discover new tissue-regenerating proteins as well as to expand our knowledge of the mechanisms of tissue regeneration.

As a fundamental analysis, this study measured and examined the mechanical property and chemical attack resistance of ceramic binder repair material at a development step through continued research. The study showed the compressive strength and bond strength of the repair material meet the standard; however, bending strength of it failed to meet the required standard. Meanwhile, chemical attack resistance displayed the excellent result.

To repair pothole failure in asphalt pavement, this study is developing high durability rehabilitation method using construction equipment and pre-cast material. The various filling material was examined to bond pre-cast repair material at asphalt pavement, performance was evaluated throuth tensile bond and shear bond test. As a result, Guss asphalt binder and two-component polyurethane material was shown a superior performance in terms of tensile bond strength, shear bond strength was two-component polyurethane material to be effective.

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.

The purpose of this study is to propose the decision making code of need for repair and strengthening in concrete bridges. First, to propose the decision making code, the guidelines and codes for a decision making of repair and strengthening and state assesment in United States and Japan were investigated and analyzed. Based on the investigated and analysis data, The decision making code of need for repair and strengthening that is divided into seven kinds of deterioration and damage is proposed. Through the proposed codes, rational and objective decision making of need for repair and strengthening is expected.