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, the analytical results do not reflect the experimental results. This is because the stress-strain curve of the concrete specimen obtained from the compression test was used as the input data for the ABAQUS. Therefore, the ABAQUS, based on the experimental results of the stress-strain relationship of concrete, predicted the load-displacement relationship without considering the reduction in load capacity.

The damage caused by the earthquake is not only the structural damage, but also the damage caused by the functional damage of the non - structural element. However, the criteria for seismic design for non - structural elements such as electrical panels are insufficient compared to those for seismic design for structural damage. In this study, the performance of the anchor bolt connecting between electric panel and concrete slabs installed in a power plant according to the occurrence of crack was investigated by experiment.

최근 건축물의 노후화에 따라 리모델링이 증가하고 있다. 이에 구조물의 품질관리 중요성이 대두되어 구조물의 안전진단 및 상태평가에 대한 관심이 증가되고 있다. 노후건축물의 정확한 진단을 위해서 구조물의 결함을 사전에 평가할 수 있는 진단평가기법이 필요하다. 이와 더불어 재건축을 위한 안전진단 기준이 개선되어 구조안전성의 가중치가 증가함에 따라 보다 신속하고 신뢰성 높은 구조물의 안전진단기법에 대한 연구가 필요한 실정이다. 초음파속도법을 이용하여 압축강도를 추정하는 연구는 공시체를 기반으로 한 연구들이 주로 이루어져 왔으며 실제 건축물이나 콘크리트 구조부재를 대상으로 한 연구는 부족한 실정이다. 본 연구에서는 비파괴검사법 중 하나인 초음파속도법을 이용하여 철근콘크리트 수직 및 수평부재로 구성된 단층 규모의 구조물을 대상으로 초음파속도와 압축강도의 상관관계를 검증하여 압축강도를 추정하고자 하며, 또한 이를 바탕으로 현장 적용성을 검토하고자 하였다. 그 결과, 초음파속도법을 이용한 구조체의 압축강도 추정 평균 오차율은 28.7%로 현장 적용성을 확인하였다. 그러나 추정의 정확도를 높이기 위하여 복합 비파괴검사법을 이용한 신뢰도 높은 진단기법의 필요성을 확인하였다.

국내뿐만 아니라 세계적인 추세로 증가하고 있는 열차의 고속화와 대량 운송능력의 요구에 따라 열차 궤도구조의 개발은 지속적으로 발전하고 있다. 콘크리트 구조궤도인 PST는 안전성과 경제성에서 그 요구조건을 충족할 수 있는 시스템으로 개발되고 있다. 따라서 본 연구 에서는 PST시스템의 각 구조부재의 거동을 분석함으로써 향후 시스템 개발 및 설계에 필요한 정보를 제공하고자 하였다. KRL-2012 열차하중과 KRC 코드에 의한 다양한 정적하중조합에 따른 응력분포 결과를 3차원 유한요소 해석을 통하여 분석하였으며, 그라우트충전층의 두께에 따른 결과 또한 제공하고자 하였다. 구조부재별로는 그라우트충전층에서 가장 큰 응력이 발생하였으며 하중조합과 두께에 따라 응력의 변화가 민감하였다. 시동하중 및 온도하중에 의해서는 KRL-2012에 의한 수직하중만 적용할 때와 비교하여 콘크리트 패널과 HSB에서 각각 3.3배, 14.1배의 발생응력이 증가하는 것으로 나타났다. 충전층의 두께가 20mm에서 80mm로 증가할 때 콘크리트 패널의 발생 응력은 4% 감소하지만, 충전층은 24% 증가하는 것으로 나타났다. 균열의 양상은 그라우트충전층에서 인장균열이 국부적으로 발생하는 것으로 나타났다. 이와같은 결과에 따라 PST시스템 개발 시에는 수직하중 보다는 수평하중에 의한 휨 및 인장거동에 세심한 주의가 필요하며, 충전층의 두께를 40mm 이상 유지함으로써 각 구조부재의 안전성을 확보할 수 있도록 한다.

This study evaluated the fiber orientation and distribution fiber in the beam members of cementitious materials using conventional and tapered nozzles. For this purpose, the specimens with 10cm × 10cm × 30cm were vertically cast to evaluate the fiber orientation and distribution coefficients on the cutting plane. Compared to the conventional nozzle, the tapered nozzle showed an improvement in the fiber orientation and distribution in the beam member.

In this paper, the flexural behaviors with substitution ratio of heavyweight waste glass are compared and evaluated in reinforced concrete members. From the results, when the heavyweight waste glass was used as the fine aggregate, the yielding load (Py) and maximum load (Pu) were less affected. However, the load capacity of the RC member was gradually reduced on the large deformed stage when all of the fine aggregate was replaced by heavyweight waste glass.

The importance of maintenance in steel structures is to be emphasized according to increase of their service time. To protect the corrosion damages, the repainting on steel bridges are usually applied every 10 to 13 years by visual inspection. However, the coating durability was rapidly decreased by airborne salt under marine environment. In this study, the time-dependence deposited salts were measured at several types and locations of structural member in marine bridge.

In this study, the orientation and distribution of fiber in the vertical members of cementitious materials were evaluated by using conventional and tapered nozzles. For this purpose, the specimens with ϕ 15 × 30 cm were cast to evaluate the fiber orientation and distribution coefficients on the cutting plane. The results showed that the tapered nozzle is more effective in improving the orientation and distribution of the fiber than the conventional nozzle.

The durability of the steel structure can be affected by atmospheric corrosion environments as temperature, humidity, airborne salt etc.. However, atmospheric corrosion environments can be locally changed depending on structural condition and shape. To estimate the local atmospheric corrosion environments depending on structural member exposed to the marine environment, corrosion level of structural member in steel bridge was examined from exposure tests.

In this study, the shear performance of the hollow slab was evaluated through experiments with the web width and volume fraction of steel fiber as variables. The lung pet bottles were used as a hollow materials. The results showed a performance difference of 19.4 to 52.3% depending on the web width, and a mixture of steel fibers showed a higher shear performance of 4.8 to 33.7%.

This research presents one of new architectural SUPER concrete structural members which were designed with nonuniform curvilinear shapes. SUPER concrete had the compressive strength of 80MPa to 200MPa, the tensile strength of 8MPa to 20MPa, and had high ductile tensile strains. Nonuniform concrete formwork were invented and specimens were manufactured to verify by test.

High-rise buildings in recent years are increasing demand for high strength. However, the higher the floor, the greater the weight of the building, resulting in structural problems. In this study, the shear span ratio was equal to 1.5, and the effect of the web width (100 mm, 150 mm) on the shear strength of I-type flexural members was evaluated.

The purpose of this study is to compare the ultrasonic pulse velocity before and after core compression test of steel fiber reinforced concrete using the ultrasonic pulse velocity method. The correlation between the column member ultrasonic pulse velocity before core test, the column member ultrasonic pulse velocity after core test, and the compressive strength of the core specimen were analyzed by fabricating a steel fiber reinforced concrete hollow column member.

The purpose of this study is to estimate the thickness of concrete slabs using the impact echo method based on the stress waves, which is one of the nondestructive test method, to evaluate the safety and construction conditions of concrete slabs. If the correlation and reliability of the impact echo method and the slab thickness are secured, it can be considered that the quality control of the concrete slab is possible in existing structures and structures under construction.

This study is to investigate and analyze the correlation of carbonation according to strength of concrete members for bridge in marine enviroment. Also depth of carbonation according to age for 100 years is estimated by carbonation rate coefficient. As a result of the measurement, it was found that the depth of carbonation decreases with increasing strength. This is because it is considered that water-cement ratio and amount of unit cement are influenced by the concrete mixing. Also, It is anticipated that rebar corrosion due to carbonation will not occur in concrete members.

In this paper, we developed a predictive model of maintenance and repair cost based on the element-level condition state by using information collected through the inspection/diagnosis of individual bridges for use in maintenance strategy analysis. The reliability of the prediction model can be improved through of big data analysis using various factors and additional data.

In order to establish preventive maintenance and to make a reasonable estimate of the required repair cost for bridges, the related history information of the existing bridge inspection and diagnosis was analyzed. It was analyzed that about 75% of the repair costs were required for the pavement, expansion joining, curb, and railings in the service area of bridges.

Corrosion durability of steel member can be related to its installed environmental conditions such as relative humidity, rainfall, atmospheric temperature, and air pollution(SO2, chloride). Also its installed environmental condition may differ depending on the shape of structural member. Therefore, In this study, to evaluate the difference in the corrosion damage according to the installation environment of steel structural members, outdoor exposure test was carried out from attaching unpainted monitoring plate and atmospheric corrosion monitoring sensor for actual steel bridge with various structural detail.

In this study, the compressive force is evaluated for the SMA surface reinforcement member which is to improve the bond capacity at cold-joint in PC member. As a result, the total compressive force can be estimated according to the number of wires.

In this study, the explosion resistance on the normal strength concrete and HPFRCC structure members were evaluated. As a result of TNT ignition test, blow out occurred in normal strength concrete structure member, but HPFRCC structure member only cracked slightly. The structure member with 180 MPa HPFRCC has excellent resistance against explosive load. Therefore, HPFRCC is considered to be applicable to national main facilities and major military facilities.