In this study, the crack occurrence in the early time in the concrete placed in a hot weather environment was discussed from the viewpoint of the temperature distribution in the specimens. Through a series of experiments it was brought to light that the relation between the ambient and end-of -mixing temperatures, heat gain due to hydration and heat loss due to vaporization significantly affected the temperature distribution in the specimens.

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This study has been made to determine the main factors related to deterioration during the service period of buildings by analyses of separation failures and fall-off accidents of actual exterior wall ceramic tile coverings which had been installed by the manual method and the prefabricated form tile installation method. The important factors closely related to the detached failures of ceramic tile coverings applied by the manual method were the shapes and sizes of lugs at the back of tiles providing mechanical bond between tiles and bedding mortar, and the derection in which the tiled walls faced.

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This paper describes the effect of siliceous coating on water permeability and pore volume of mortar substrate. Coefficient of permeability and pore volume were measured for evaluation of watertightness of them. Coefficient of permeability and pore volume of coated mortar were obviously less than those of non-coated one. Effect of siliceous coating reached the inside 5 to 10 mm of coated mortar. Reduction of pore volume was caused by the decrease of capillary pores within the size range 0.1 to 1μm. Relationship of them can be described by the equation y = 3.25×10^<-6>x^<3.39>, where y is coefficient of permeability and x is pore volume.

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Attenuation relations of peak ground acceleration and velocity are examined based on records from the 1985 Chile (M 7. 8) and the 1983 Nihonkai-chubu (M 7. 7) earthquakes for the purpose of predicting intensities of strong-motion during large earthquakes in subduction zone. The relations obtained from the Chilean records show that the effects of site geology and source directivity are significant. The relations from the Chilean records are consistent with the Japanese records when the effects of site amplification on the Japanese records are removed. The comparison of the relations with those of previous studies shows that the attenuation relations derived from U. S. data are different from those for these two earthquakes.

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As shown in Part 1, a well-designed composite unbonded bracing has a large ductility in an elasto-plastic range under cyclic loading. In Part 2, the conditions for the encasing reinforced concrete to make a core steel realize its general yield strength without premature over-all buckling are analytically studied. This paper also proposes a design method for unbonded composite bracings.

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The mechanical properties such as yield point, tensile strength and elongation of the recently produced deformed steel bars are surveyed in this research based the testing data obtained at the two testing organizations in Japan. As the results of this experimental research, the mechanical properties of deformed steel bar produced since its revision of JIS in 1985, were shown as a form in normal distribution and several useful knowledge have been given through this research.

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In order to evaluate ultimate strength and ductility of flexurally failing reinforced concrete members, the use of axial stress-strain relation models of concrete, which represent behaviors of concrete practically as far as in the range of descending part after maximum stress, will be necessary. In this study, two series of experiments were conducted in order to propose a more practical stress-strain relation model for square confined R/C columns. In series A, 15 square columns, each 150 mm square by 530 mm high, containing different arrangements of square steel hoops, were subjected to concentric axial force only. In series B, 26 square columns, each 150mm square by 530mm high, with different concrete strength (400, 600, 800 kg/cm^2) and different reinforcement strength (4000, 8000, 12 000 kg/cm^2), were subjected to concentric axial force only. The stress - strain relation model was proposed based on the results of experiment series A and B. The increments of maximum stress and axial strain at maximum stress by hoop confinement were considered. The effects of square confinement were also considered in this model. Also, the negative stiffness of the descending part after maximum stress could be evaluated using confining stress by hoop reinforcement at the axial stress peak point. The ultimate axial stress could be evaluated using maximum confining stress by hoop reinforcement.

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Loading tests of full scale specimens of the anchorage zone of prestressing tendons were carried out. Factors.of the area of the cross section of members, concrete strength, and amount of lateral reinforcement (amount of spiral and hoop reinforcement) are considered to affect the cracking behavior and ultimate strength of the anchorege zone, and those factors were taken as parameters. From the relations between each parameter and the behaviors of specimens, formulae by which cracking and ultimate strengths can be predicted are presented here. Based on a new idea of cumulative strength of concrete, and spiral and hoop reinforcement, the formulae were derived. Proposed formulae for cracking and ultimate strengths were examined by the application to the experimental data which ware published preveously, and it was confirmed that they gave.good prediction and that they were satisfactorily applicable.

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Experimental and analytical studies have been carried out to estimate the yield and ultimate strength of steel beam to concrete-filled square tube column reinforced with inner ring stiffener. The strength capacities of the connections can be estimated by the superposition of the capacity of column flange which is calculated with the Yield Line Theory and that of inner ring stiffener. The analytical yield and ultimate strengths agree comparatively well with the experimental yield and ultimate strengths respectively.

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The relation between the energy absorption capacity and the maximum horizontal deformation of steel cylindrical structures after buckling is made clear based on the results of experiments and earthquake response analysises. The ultimate strength of steel cylindrical structures can be estimated by equating the energy absorption capacity of structures to the seismic energy input.

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Dynamic analyses of a pile group embedded in a homogeneous soil are carried out by the advanced method in which the pile-soil-pile interaction effects are included by using the Green's function derived from the thin layer formulation. The effective input motions of a pile foundation are computed and the dynamic characteristics are studied from view points of the effects on the diameter of a pile, the pile space and the number of piles. As the results, it is understood that the magnitude of the input motions is reduced in the higher frequency range, and the redaction effect is significant as the diameter of a pile is increasing, the pile space is getting smaller and the number of piles is increasing. Furthermore, the earthquake response analysis of the 5-story building supported by 4 × 4 pile group is carried out, and the influence of the input loss due to the pile group is discussed by observing the maximum response values and the transfer functions of the building.

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Buckling strength of cruciform section steel plates in plastic range whose mechanical property in tension has plastic-flow is theoretically obtained. Shear modulus and flexural rigidity, both of which were derived previously by the author, are applied for the present problem. The result shows that a buckling mode exists which gives lower critical value than that of pure torsional buckling. Present theoretical study is compared with test results for miled steel already published by the author. Theoretical critical value fairly agree with test results. The predicted b/t ratio of the plate which buckles just at the onset of strain-hardening coinsides perfectly with the test result.

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When discussing system truss fatigue, fatigue failure of bolts poses the most serious problem. This paper tries to clarify the fatigue properties which is peculiar to bolt joints of system trusses. It explains fatigue tests conducted on actual connection models and analyzes fatigue properties involved.

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Recent buildings have been more unburnable than before because changing of construction methods, progress of building materials, preparation of the related laws and regulations and so forth. But buildings have been more unextinguishable contradictory, and extinguish time need more longer than before. There are problems ; Is not the water application ratio low ? How much is the water damage area even if the water is used for extinguishing ? If we survey these problems, it is useful in order to make fire fighting planning. Then we investigated these items as a part of basic study on the extinguishing of the building fire.

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In order to grasp the present circumstances and problems of computer utilized structural calculation, we applied four kinds of simple building models we call 'benchmark structures' to various structural design programs actually used in various companies. We point out the following from our studies and investigations ; 1) We confimed conspicuous difference among the calculated results of stress analysis and the 'check and design' results of member section. 2) Calculated results of aseismic characteristics; modulus of eccentricity, story stiffness ratio and story deformation angle were also found very different, because of various interpretations of their definitions.

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