The purpose of this study is to develop interlocking block pavement which can improve thermal environment in urbanized area. This pavement has permeable part and water raising part due to capillary action from underground to surface. The surface temperature of this pavement is reduced by latent heat of surface water. In this study, asphalt pavement, concrete pavement, permeable interlocking block pavement and proposed interlocking block pavement were made on field, and surface and underground temperature of each model pavement were measured.

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The carbon fiber reinforced composite rod (CFRC rod) was manufactured by impregnating with cement paste into different types of continuous carbon fibers. Normal portland cement and grout cement were used to produce CFRC rod. Workability for producing of CFRC concrete beam was improved by using carbon fibers as a form of rod. When the grout cement was used in the CFRC rod, the failure bending moment and the deflection of CFRC concrete beam at failure were larger than those of CFRC concrete beam using normal cement in the CFRC rod. The failure bending moment of CFRC concrete beam can be estimated by modelling as laminated beam when a CFRC concrete beam fails by cutting of CFRC rod.

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Since chloride induced deterioration of structures are mainly governed by the local atmosphere where target structures are located, the parameters need to be obtained by using actual data in situ.
The data of deterioration obtained from existing concrete structures of thermal power plants over 20 years along Tokyo Bay are analyzed and studied in this paper.
Then, the parameters such as chloride ion density, diffusion coefficient and corrosion speed of reinforcement to chloride induced damage are investigated.

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The shear resisting model for reinforced and prestressed concrete beams using steel bars has been proposed. This model is based on the shear resisting model for non-prestressed and prestressed concrete beams reinforced with FRP rods which was proposed previously by the authors. In the proposed model, the shear strengths of beams in which yielding of shear reinforcement takes place can be calculated considering equivalent stiffness of shear reinforcement. It was confirmed that the shear resisting model could predict experimental shear strengths of reinforced and prestressed concrete beams with good accuracy.

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Precooling method is thought to be an effective way to control thermal cracks due to the heat of hydration for mass concrete structures. The authors executed a fundamental research on new type of precooling method by use of Dry Ice as a cooling medium. This paper describes cooling efficiency, carbonation, and workability of cool-down concrete when using Dry Ice. From this fundamental study, it is clarified that Dry Ice should be utilized for manufacturing chemically inert aggregates to avoid acceleration of carbonation of cool-down concrete and to assure its workability, and that its cooling procedure and process are proposed in the stage of actual application.

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The objective of this research is to propose the method for estimating the water retaining factor and the flowing factor, which are properties of powder concerning paste flow, with particle size distribution, particle shape and property of hydration of cement. The results obtained are as follows: The water retaining factor is proportional to the product of the index represent particle size and the index represent form of particle size distribution, and its proportionality constant represent particle shape and property of hydration. The flowing factor is proportional to the product of the index represent particle size and the index represent particle shape and property of hydration, and the constant term represent surface condition of powder supposing its proportionality constant is fixed.

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The super-tough mixed concrete that was compacted with high vibration energy has the property of not happening plastic deformation easily by external force just after compaction. In the period of setting and early period hardening condition of concrete by utilizing the property, the composite pavement is made by carrying out an overlay of hot-mixed asphalt concrete. Furthermore, the term of the pavement construction is able to be contracted by opening to the traffic without curing of concrete. In this study, it was confirmed that it had the effect that accelerated the occurrence of bending strength of concrete and the progress of hydration reaction, even if the heating and the action of repeated loading by wheel load were given without putting the curing period of concrete.

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Prior to casting concrete, thermal stress analysis is often performed in order to examine a possibility of crack occurrence due to cement hydration. Many parameters are involved in the analysis, for which their average values are chosen considering exiting references or the experiment conducted for that purpose. However the values could differ depending on the environmental conditions at construction sites as well as materials in use.
The objective of this study is to demonstrate the effectiveness of the inverse analysis algorithm for estimating thermal parameters from on-site measurement data and to examine the results obtained.

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In the present study, accelerated tests of GFRP were carried out in order to clarify the penetration of alkali in GFRP rods. Sections of GFRP rods were observed using an Electron Prove Microscope Analyzer.
From experimental result, it was known that Alkali penetrated into GFRP and corroded glass fibers in the rod. And it was clarified that the deterioration of GFRP accompanied by the decrease in tensile strength is due to the penetration of alkali depending on the glass fibers present in them. The alkali penetration process of model based on Fick's first law. The decrease in tensile strength of GFRP due to alkali could be estimated by the proposed model.

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When reinforced concrete structures have been suffered from chloride induced corrosion, repair works were done. However, there is possibility that the bars around the joint will corrode again with macro-cell corrosion, because the concentrations of contained chloride ions are different between the new materials and old concrete members. Therefore, in this study macrocell mechanism and macrocell corrosion rate of steels in concrete members are experimentally investigated. As a result, it can be confirmed as follows:
(1) Influence of W/C, materials and chloride ion on macro-cell initiation mechanism.
(2) Influence of humidity and temperature of surrounding on macro-cell corrosion rate.

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Characterization of powder is essential for proportioning the self-compacting concrete. In particular, the capability of water retention is the most basic parameter for the characterization. This paper deals with what properties of powder affect the water retention capacity mostly and how they do. Out of several factors, particle shape and distribution of particle size are selected as key factors, and they are characterized by introducing a shape factor and a statistic measure. It is concluded that those factors are effective to make a quantitative representation of how particles are packed in a unit volume, and then, to construct a model how water is retained on the surface of particles.

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Uncommon cracks with an average width 0.2mm and an average crack interval 0.5m, were detected on the RC barrier walls over the steel decks of our Hanshin Expressways Bay Route. These cracks increased in number especially in summer. It was also found by the analytical and field studies that these cracks occurred because RC barrier walls fixed tightly to the steel decks made a move following the steel deck's deformation behavior as a result of the temperature rise. Our solution was to introduce joints at 10m intervals and to utilize expansion concrete. These measures were found to be effective by a follow-up inspection, with an average crack width reducing to 0.14mm and an average crack interval increasing to 1.18m.

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This experimental study has been conducted on preventing cracks induced due to the heat of hydration of cement during construction. A large cylindrical reinforced concrete silo was used to assess the effect of several improved construction methods. Numerical analysis with high accuracy was conducted for the measured stresses, temperature, etc.. This numerical method, in which FEM was used can predict the thermal stresses of practical significance. It was noted that more detailed conditions on surface heat convection such as, influence of weather and curing conditions, must be considered to predict the actual value.

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This paper describes experimentally and analytically the flexural behavior of precast segmental externally prestressed beams. From the test results, it was observed that there is little difference in the flexural behavior between epoxy joint and dry joint. The failure modes of such beams are brittle due to non continuity of reinforcement across the segments. The ductility of the member and failure mode could be improved by confining the concrete in the compression zone. Using the above method, the flexural behavior of two span continuous beam was clarified experimentally.

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The objective of this study is to develope PC members using aramid ropes as externalcables. First, static and dynamic characteristics of PC members using aramid ropes as external cables was investigated. It was found that aramid rope is more suitable than ordinary FRP when it is used for external cable. And, the ductility of PC membersusing FRP as external cables was improved by method using transverse CFRP to confine concrete. Second, it was found that the analytical method based on the compatibility of deformation and change of ecentricity showed a good agreement with test results.

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The effective use of converter furnace slag has not been made yet, as it has extraordinary expansive nature due to the hydration of free CaO. In this paper, it has been made clear that the expansive nature is reduced greatly by the method of steam aging and two types of new upper base materials using the improved converter furnace slag have almost the same properties as those of HMS-25, whichis the ordinary upper base material made of blast furnace slag. Furthermore, the results (CBR test, plate bearing test and Benkelmann beam test etc.) of the tentative pavement test with the two types of new upper base materials are concerned.

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The basic properties in heat and strength of concrete with highly pulverized blast-furnace slag, silica fume, superplasticizer, and low-heat cement, are extensively studied. The results revealed that it is possible to produce low-heat, extremely high-strength concrete even at early age by properly exploiting the properties of the materials. The results in low temperatures also showed that concrete of this type has much higher strength than that of conventional types. The mechanism of low-heat and high-strength is comprehensively explained by hydrates, pore structures, and combined water content.

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The purpose of this study is to define rationally the ultimate limit state of reinforced concrete structure such as pier or column and to propose the damage index which is a rational measurement of safety.
In this study, ultimate limit state due to flexure is defined as the push-out of longitudinal bar, and one due to shear is defined as the yield of shear reinforcement.
Furthermore, new damage index on the basis of these definitions, which are verified by the experimental data, and the method of application of the damage index to the practical seismic design for reinforced concrete structure are proposed.

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In order to investigate the bond strength of reinforced steel and concrete of a reinforced concrete building, which is constructed in a continuously vibrating environment, we implemented room tests by way of changing vibrating times, directions and methods.
Based on these results, we studied how the bond strength might be impacted when changing vibration frequency and ac celeration, and we identified the level of vibration by lowering the bond strength.
In addition, as an in-situ test, we executed a pull-out test of the reinforced steel using a model wall at an internal combustion power station which is scheduled to undergo additional construction.

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A prestressed concrete girder with a steel section in its compressive zone is developed for bridges. The girder has an advantage of having less depth than the ordinary prestressed concrete girder. This paper reports about bending, shear and fatigue behavior of the girder based on experimental data. The connection between steel and concrete is achieved by introducing holes in the steel section. The paper also reports ‘Push out test’ performed to ensure the strength of these connections.

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Granulated blast furnace slag powder activated by some alkalies presents high hydraulic activity and can be used as a high strength alkali-activated cement (AS cement). However, because of different hydration mechanisms, the strength characteristics of AS cement differ from those of portland cement. In this paper, the strength characteristics of AS mortar and/or concrete and factors effecting on the strength such as hydraulic activity of the slag, fineness of slag, types and dosages of activators, curing temperatures, compatibility to other admixtures, W/C, are presented.

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The linear viscoelastic properties of asphalt binders are analyzed based upon two different methods: (1) nomograph and (2) dynamic mechanical analysis. The former one is an empirical procedure which has been used by paving technologists for a long time while the latter one is used to directly measure the dynamic response of materials. The application of viscoelasticity to asphalt cements is explained in terms of master curves. It is shown that data obtained from nomographs are inaccurate and misleading compared to measured data. Several models are further presented to predict the linear viscoelastic properties of asphalt binder and found that one of these models can be adequately used for asphalt binders.

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It is known that bridging is a dominant mechanism in the fracture of concrete. The material property related to bridging is the tension-softening relationship which is the relationship between the transmitted tensile stress across the crack surface and the crack opening displacement. In this paper, a method to indirectly obtain the tension-softening curve from the bending test of a notched beam is proposed. The method is applied to reported results, and agreement is observed between the tension-softening curves by the proposed method and the modified J-integral-based technique. The method is also applied to bending tests of SFRC beams, and results are compared with those of direct tension tests.

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In relation to disastrous damage of reinforced concrete (RC) columns due to recent Hanshin-Awaji Earthquake, high-frequency behavior of RC beams subjected to impact loading is reexamined. Thus, the effect of high-frequency horizontal motions on the columns is inclusively studied, solving RC beams in the elastic range by BEM. From the dimensional analysis, it is suggested that the local failure mode of the columns due to horizontal motions could result from high-frequency earthquakes over 10Hz. The stress analysis suggests spalling failure of cover concrete due to high-frequency bending motions and the high shear stress zone localized at one end due to the higher frequency motions.

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