PURPOSES: The purpose of this study is to validate the design criteria of the concrete modular road system, which is a new semi-bridgetype concept road, through a comparison of numerical analysis results and actual loading test results under static axial loads. METHODS : To design the semi-bridge-type modular road, both the bridge design code and the concrete structural design code were adopted. The standard truck load (KL-510) was applied as the major traffic vehicle for the design loading condition. The dimension of the modular slab was designed in consideration of self-weight, axial load, environmental load, and combined loads, with ultimate limit state coefficients. The ANSYS APDL (2010) program was used for case studies of center and edge loading, and the analysis results were compared with the actual mock-up test results. RESULTS : A full-scale mock-up test was successfully conducted. The maximum longitudinal steel strains were measured as about 35 and 83.5 micro-strain (within elastic range) at center and edge loading locations, respectively, under a 100 kN dual- wheel loading condition by accelerating pavement tester. CONCLUSIONS: Based on the results of the comparison between the numerical analysis and the full-scale test, the maximum converted stress range at the edge location is 32~51% of the required standard flexural strength under the two times over-weight loading condition. In the case of edge loading, the maximum converted stresses from the Westergaard equation, the ANSYS APDL analysis, and the mock-up test are 1.95, 1.7, and 2.3 times of that of the center loading case, respectively. The primary reason for this difference is related to the assumption of the boundary conditions of the vertical connection between the slab module and the crossbeam module. Even though more research is required to fully define the boundary conditions, the proposed design criteria for the concrete modular road finally seems to be reasonable.

In this experiment, a highly porous scaffold of biphasic calcium phosphate (BCP) was prepared using the spongereplica method. The BCP scaffold was coated with 58S bioactive glass (BG) and sintered for a second time. The resulting scaffold was coated with gelatin (Gel) and cross-linked with [3-(3-dimethyl aminopropyl) carbodiimide] and N-Hydroxysuccinamide (EDC-NHS). The initial average pore size of the scaffold ranged from 300 to 700μm, with more than 85 % porosity. The coating of BG and Gel had a significant effect on the scaffold-pore size, decreasing scaffold porosity while increasing mechanical strength. The material and surface properties were evaluated by means of several experiments involving scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) and X-ray diffraction (XRD). Cytotoxicity was evaluated using MTT assay and confocal imaging of MC3T3-E1 pre-osteoblast cells cultured in vitro. Three types of scaffold (BCP, BCP-BG and BCP-BG-Gel) were implanted in a rat skull for in vivo evaluation. After 8 weeks of implantation, bone regeneration occurred in all three types of sample. Interestingly, regeneration was found to be greater (geometrically and physiologically) for neat BCP scaffolds than for two other kinds of composite scaffolds. However, the other two types of scaffolds were still better than the control (i.e., defect without treatment).

이 연구는 현재의 온도 데이터를 사용하여 각 지역의 최저 최고 온도를 설정하여 국내 교량 설계시 이를 적용할 수 있도록 하기 위해 확룰적 방법에 의해 온도 하중을 제안하는데 그 목적을 두었다.

This study examined the collapse of bridge under extreme events. As a result, numerous bridges collapsed by scour, collision, fire and earthquake. The research team studied four cases of previous bridge collapse and restoration following extreme events. Finally, the disaster type factor were selected.

In this study two kinds of cases were selected in order to develop roadway system. Specifically two boundary conditions were considered with varying support offset. In each case, relatively loading Dead load, Live load, Temperature load, displacement and reaction force were analyzed at the end of slab. As a result, this study performed optimization review of roadway connection.

In this study, shear assessment equation of reinforced concrete interior beam-column joints without shear reinforcement using high ductile fiber reinforced mortar based on the test results was proposed. Suggested equation was proposed to modify Hegger's seismic design equation. It was reflected the effect of high ductile fiber incorporated