The purpose of this study is to clarify the influence of environmental condition and mix proportion on the progression of deterioration of the hardened cement paste and mortar under the acid environment. In this study, the cement paste and mortar specimens varied by W/C and S/C were exposed into several types of acid solution considered actual acid environment. By following the progression of deterioration of the specimens using some evaluation indexes about acid deterioration, the influence of the environmental condition and the mix proportion on the progress of deterioration of the hardened cement under some acid environments were discussed. As a result, it was clarified that the progression of deterioration was hastened when the W/C was high or the S/C was low through the investigation result of setting acid solution concentration near actual environment. In addition, it was turned out that the progression of deterioration was high when the nitric acid was contained in the acid solution.

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Railway RC rigid-frame abutment is a rigid frame structure in one span often used to support the girder that steps over wide road. This structural type has the anxiety that seismic behavior becomes complex due to the difference of each column section and the bias of mass arrangement by differing span of girder on both sides. In this study, the influence of the torsion by earthquake was examined by the analysis that used the three-dimensional frame model. As a result, it was clarified that the torsion rigidity of the columns influenced the amount of the torsion in the columns. And, it was shown that there was a possibility that a large amount of torsion reinforcement is needed by the bias of the mass arrangement.

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This study aims to examine a fatigue life prediction method based on a mechanistic-empirical approach for HMA. Field surveys and lab tests were conducted. It was found that fatigue cracking depends greatly on the mixing proportions of components of the bottom layer. By lab test, it was confirmed that HMA with different mix proportions differ to a statistically significant degree in the number of cycle to failure, and fatigue failue criterion for HMA based on damage theory was obtained. With this criterion and data obserbed at field survey, calculations were conducted to predict the fatigue life. Comparing the calculated fatigue life and the obserbed fatigue life, it was considered that they agree well.

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UFC has the properties of high compressive strength, high tensile strength, and high ductility. Due to the properties of UFC, flexural behavior of RC, PC beams and plain UFC beams, will be different from conventional concrete beams. The aim of this study is to clarify the flexural behavior of UFC beams, the size effect of flexural resistance of UFC and the tension stiffening effect for UFC due to the short fiber reinforcement. Then, flexural loading tests and double pull-out tests were carried out. Furthermore nonlinear FEM analyses of RC and PC beams using UFC with tension stiffening effect were carried out.

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In this study, the mortar specimens exposed into 0.1 to 0.5% concentration of sulfuric acid solution for up to 12 months were evaluated by several degradation indexes, in order to clarify the influence of the concentration of sulfuric acid solution and mix proportion on the progression of deterioration of hardened cement. According to the test results, it was found that the progression of deterioration is classified into three types, namely expansion-spalling type, penetration-dissolution type, and penetration-undissolution type. Furthermore, it was clarified that the sulfuric acid resistance of hardened cement is high in the case of (1) low water-cement ratio, and (2) high sand-cement ratio.

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The theoretical solutions for pavement structural analysis such as GAMES and BISAR have been developed using a cylindrical coordinate. This coordinate is suitable for a distributed load over a circular area. The objective of this paper is to develop a solution for elastic multilayered system subjected to a distributed load over a rectangular area. Three components hof displacement which satisfies Navier's equation are expressed by Neuber-Papkovich functions. One vertical and two horizontal uniform loads are considered in this paper. In order to verify the validity of the solution, the results are confirmed with those obtained from GAMES.

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In this paper, the uniaxial compressive behavior of confined concrete with the corroded reinforcing steel, which is to apply for the analysis of load-carrying behavior of RC beam with corroded reinforcing steel in the flexural compression zone, was investigated. The compression behavior of corroded confined concrete, which is strengthened by the confinement using CFRP, was also investigated. The result indicated that the concrete section, which was damaged by the cracks due to corrosion, led to the change in the compressive characteristic. Furthermore, the strengthening by CFRP sheet confinement can improve uniaxial compressive capacity of confined concrete with the reinforcing steel corrosion.

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Physical and chemical surveys of concrete were conducted on the upper crests of approximately 10 to 40 year old harbor breakwaters on coastal areas to analyze the progress of scaling. These surveys indicated that concrete with a compressive strength of 35MPa or more has high resistance to scaling. By integrating the results of the multiple regression analysis of surveyed data and affectors multiplied by weighting factors, we propose a scaling progression index (γ). Breakwaters with a logγ of approximately 0 or more show large scaling, confirming its effectiveness as a deterioration prediction method. This paper also discussed important points regarding the assessment of internal damage of concrete structure.

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