Using several types of Portland cement and blast furnace slag powder(BFS), relationship between the hydration of BFS blended cement and the microstructural evolution were studied. The rate of consumed calcium hydroxide from BFS hydration do not have the constant value, gradually decreases as hydration progresses. The capillary pore volume of BFS blended cement is larger in lower region of hydration degree, and remarkably decreases as hydration progresses. The amount of drying shrinkage of Portland cement and BFS blended cement mortar can be explained by the volume fraction of C-S-H gel in solid phases, the larger shrinkage of mortar with the lager amount of C-S-H.

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Finishing work greatly changes slab surface quality which influences floor performance. And, characteristics of concrete also greatly influence finishability. From such backgrounds, relations between mix proportion and finishiability were examined.
60 kinds of mix proportion used on actual sites and prepared for the examination were set, and finishability of them were measured. As a result, those were shown that unit water content and admixture addition ratio influenced finishability directly, and finishability was predictable clearly by a combination of both. Moreover, it was generally thought that water-bond ratio and fluidity were causes, the combination turned out to be the direct cause.

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Concrete with a design strength of 100 to 150 N/mm² made using low-heat portland cement and silica fume (LSF) was subjected to thermal histories with different maximum temperatures (T_max) to examine their autogenous shrinkage properties. The autogenous shrinkage properties were found to significantly change when T_max exceeded 45 to 60°C. Comparing these results with past studies using portland cement, the authors clarified the autogenous shrinkage properties of LSF concrete and proposed a technique for their prediction by modifying conventional equations. Furthermore, the applicability of the proposed method was verified.

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During film formation of polymer-cement waterproofing membrane, hydration of cement and hardening of polymer simultaneously occur. The key of the process is consumption of water by hydration and evaporation from the surface of a membrane. This study is focused on the influence of evaporation rate in dependence on curing conditions given to structures and mechanical properties of polymer-cement waterproofing membrane. Three polymer-cement membrane mixes were prepared with different ratios of cement, polymer and water, and were cured at 20°C with levels of relative humidity 25%, 60% and 98%. These materials were investigated through EPMA observation and by performing tensile strength tests. The results indicate that even the specimens of the same mix have diverse structures and mechanical properties. Furthermore, a simulation model adopted water reduction by hydration and evaporation was developed. The results of simulation were in good agreement with experimental observations.

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This paper deals with the fire resistance of repaired components by polymer-modified cement mortar. The experiment examine fire test for two hours, confirmed the damage conditions and the temperature distribution of repair sections, and adhesive strength.
As the result, the monolithic property of repair section depends on its size and thickness, the case of large and thin is relatively danger. The temperature distribution in the repair section is relatively low compared with an ordinary concrete and mortar, so harmful influence to the structural safety in fire is low from the viewpoint of the temperature of the reinforcing bar.

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In this study, to develop the non-destructive method for evaluating moisture content of concrete structures, fundamental study of application of terahertz radiation was conducted. The samples of hardened cement paste with three types of Portland cement and three different water to cement ratios were prepared. With the terahertz time-domain spectroscopy, dependency of frequency on the fraction transmitted and applicable scope are evaluated. As a result, it is experimentally confirmed that 0.1 and 0.05 THz are the better frequency for evaluating moisture content of hardened cement paste, and the scope and the method for evaluating water content in hardened cement paste are proposed with characteristic values. This proposed method can be applicable regardless of cement type and water to cement ratio.

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The purpose of this paper is to investigate the flow mechanism for maximum negative pressure on the upstream area of an elliptic structure by LES analysis, when the oblique flow attacks. First the present LES model is validated for the prediction of the pressure characteristics on a three-dimensional elliptic structure in boundary-layer turbulence through comparison with the experimental data. Next, the flow characteristics which induce the maximum negative pressure are investigated by using the computed results. Furthermore, in order to clarify the fundamental flow characteristics associated with occurrence of the maximum negative pressure on an elliptic cylinder, LES analysis for a two-dimensional elliptic cylinder in uniform flow is carried out as a function of the Reynolds number and the wind direction. As a result, it is clarified that the characteristics of the flow separation and reattachment associated with the change in the curvature of surface of an elliptic cylinder cause the maximum negative pressure.

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A practical analysis model to simulate the cyclic behavior of a linear viscoelastic damper is proposed. It utilizes the classical Kelvin body with adequately specified stiffness and viscosity. Part 2 paper discusses the modeling method and its accuracy using a multi-mass system having the damper, supporting member, and elastic or inelastic frame. The performance of the model is examined by comparing the analytical results with those obtained from the accurate fractional-derivative constitutive rule. Although the frequency-sensitivity of Kelvin body differs considerably from the actual sensitivity, the model is found to produce reasonably accurate results under both sinusoidal and random excitations.

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An analytical model that expresses mechanical properties, especially pressure dependent characteristics, of high damping rubber bearing in a simple form was proposed. The model was built through drawing regression equation based on a series of full size performance tests. It is possible to express the pressure dependent characteristics with a sufficient accuracy by including explanatory variables of products of the share strain and the pressure. Moreover, influence of load experience in the tests, and applicability to the bi-directional loading were also discussed.

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This paper introduces a simple design method for tuned dynamic mass(D.M.) systems with very large added mass ratio which is the value of D.M.(rotating inertial mass) to mass of the main structure. The method is constructed on the bases of rule of geometric mean and rule of difference/sum for the natural periods computed under the particular conditions of viscous damping factors of h_d= 0 and h_d= ∞. The rules are derived from the properties of the invariant point theory. The paper shows that the structures can be designed by the proposed method, which hold viscous damping factors more than 0.2 for the 1^st and 2^nd modes.

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To estimate the load-settlement relationship of the pile end, the extent of ground below the end which influences the relationship should be considered. The consideration is more important in case of layered ground. In the paper, the extent is investigated by FEM analysis and pile load test results. On investigation by FEM analysis, 24 models of layered ground and the results show that the extent of the influence is different between two cases of layered ground. In the one case, standard penetration test N-value of a layer is equal to or larger than one of the upper layer. In the other case is opposite. It tells us the point for estimating the bearing capacity that the different average N-value should be adopted between the two cases. And the point is explained by a proposing model that pile end settlement is accumulated compressive deformation of layers. The pile load test result also shows that the point is proper.

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The final goal of this study is to develop an evaluation method of seismic damage in reinforced concrete structural members which is essential in accurate estimation of reparability limit state of R/C buildings damaged due to earthquakes. Firstly, general concept and outline of damage evaluation procedure of ductile R/C members were presented. Part1 focused on proposal of an analytical model for crack length evaluation in ductile column and beam was developed. The analytical model of crack lengths consists of two parts; models in and outside the plastic hinge regions which correspond to flexural spring and shear spring, respectively, for the frame analysis under and/or seismic loads. The proposed models calculated total crack length from the predicted number and average length of flexural and shear cracks. Finally, crack length evaluated by the proposed method was compared with authors' column and beam specimens and relatively good agreement was observed.

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Reversed cyclic loading tests were conducted on six prestressed concrete beam-interior column joint assemblies that failed inside the joint cores. The variables adopted in the tests were aspect ratio of joint cores and concrete compressive strength. No significant differences in the maximum shear stress of the joint cores were observed between the beam-column joint assemblies. Finite element analysis of the beam-column joint assemblies was performed. The analytical results showed the presence of 45° truss mechanism inside the joint cores. Equations using 45° truss model was proposed for predicting the ultimate strength of prestressed concrete beam-interior column joint assemblies that failed in shear inside the joint cores. The equations were compared with test data on 26 prestressed concrete beam-interior column joint assemblies that failed in the joint cores. The test results agreed well with the estimations.

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This paper presents seismic response of steel structures including fractures at tubular braces. We apply pseudo dynamic test of substructure to collaborative structural analysis system in order to conduct high-accuracy analyses because it is very difficult to predict fracture life of steel members accurately. Analyses of three-story steel moment frame with loading tests of tubular braces are conducted using various earthquake intensities. The results show tubular braces are hard to fracture under severe earthquake even if the braces have low deformation capacity, and affects of the brace fracture after local buckling is limited because the strength is considerably degraded.

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It may well be that in cases where huge long period ground motions are input into a high-rise building structure, its members will be subjected to many cyclic loading in plastic range. This study was carried out with the object of making clear the energy absorption capacity of steel beams subjected to cyclic bending moment. A series of tests were conducted under the condition of various types of loading sequence. On the basis of test results, the authors proposed a method for estimating the energy absorption capacity of steel beams subjected to arbitrary cyclic bending moment.

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Previous studies have suggested that rocking vibration accompanied with foundation uplift motion might reduce the seismic damage to buildings subjected to severe earthquake motions. Based on this knowledge, the authors have proposed the uplift rocking system that makes use of the uplift yielding mechanism of specially designed flexing base plates, and showed that the yielding base plates work as hysteretic dampers. In this paper, the authors examine the hysteretic characteristics and cumulative plastic deformation capacity of the yielding base plates for the uplift rocking system using the results of the statically cyclic loading tests. It is shown that the proposed calculation provides the approximate estimation of the mechanical properties of hysteretic behavior of the yielding base plates, and that the haunched base plates improve the cumulative plastic deformation capacity compared with non-haunched base plates.

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