The influence of quantity and shape of coarse aggregate and flowability of mortar on flowability of self-compacting concrete is investigated in this study. The coefficient of thickness of mortar layer is introduced based on coefficient of coarse aggregate's shape, quantity of coarse aggregate and solid content in coarse aggregate. The coefficient of coarse aggregate's shape is introduced by projection circumference, projection area, volume and grading of coarse aggregate. The flowability of self-compacting concrete can be estimated by coefficient of thickness of mortar layer and flowability of mortar.

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The strength development of concrete in mass precast concrete element is different from that of concrete in thin precast concrete element. This is attributed to the difference in temperature history caused by the internal storage of heat of cement hydration in the mass precast concrete element. When determining a proportioning strength of concrete in mass precast concrete, conventional correction values of concrete strength are not available. This paper proposes a new method for determining a correction value of concrete strength at the age of 28 days that is suitable for mass precast concrete.

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The properties of coarse aggregate - mortar boundary in concrete affect its fracture mechanism. In this paper, the authors propose a new visco-elasto-plastic suspension element method (VEPSEM) considering the interfacial properties in order to investigate the effect of coarse aggregate - mortar boundary on the fracture behavior of concrete. The applicability of this new analytical method is confirmed by comparing with previous analytical results. As the result, it is shown that the effect of coarse aggregate-mortar boundary can be expressed more accurately by using this new analytical method.

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In this paper, properties of frost damage at early age and strength development and thermal crack were studied, for purposes of application to the mass concrete of low-heat cement in cold weather, by means of concrete experiments and temperature analysis by finite element method. The experiments and the analysis result showed that the strength for resistance to frost damage at early age was 5N/mm^2, the concrete strength correction value in terms of curing temperature was calculated approximately, and was effective in the resistance of thermal crack. And then, the application ranges of construction procedures were investigated.

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This paper studies characters of thermograph, which measured by three band wavelength infrared rays on the diagnosis for external walls. For smooth surface, long-wave band and short-wave band receive influence from the reflection. Other way, middle-wave band hardly receive the reflection, by function of the air as the filter to cut noise origin. So, middle-wave band has the advantage to diagnose smooth tile surface. And it's hopeful to improve the precision to find removed tile.

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Shrinkage compensating high fluidity concrete is a new type of concrete for construction joints which enables the joint to bond firmly in the inverse placing construction method. With the aim of examining mechanical behavior in horizontal joint inversely cast with shrinkage compensating high fluidity concrete, the bending test and shear test were conducted. As the result, it has become clear that the flexural strength and shearing strength of horizontal joint inversely cast with shrinkage compensating high fluidity concrete is equal to the strength of the construction joint of normal placing method.

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In this paper, the effect of surface properties on the visual evaluation of building stone finishing was investigated. The factors affecting the visual evaluation such as roughness, gloss, brightness, naturalness, comfort of natural stone surface were analyzed by performing the sensory test using the various natural stone specimen which were changing the stone type, surface finishing method and surface pattern. Physical values of surface roughness, glossiness and surface color were measured and the relationship between them and the results of sensory test was considered. It was cleared that the visual evaluation of stone specimen is affected by the various factors, visual surface roughness is not related to the physical surface roughness, visual gloss is related to the physical value of gloss, visual brightness is related to the value of the surface color and comfort depends on the many factors of stone types, surface roughness, color and pattern.

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A simplified method to assess the seismic performance of structures with added viscous or viscoelastic dampers is proposed. It is based on the momentary energy dissipated in structures with/without additional dampers and evaluates the reduction ratio of maximum acceleration of earthquake ground motions. The changes in structural stiffness, damping factor and seismic momentary induced energy are considered to relate the proposed method to the maximum displacement response of damped structures. Extensive time history analyses on the single-degree-of-freedom system with additional viscous or viscoelastic dampers are performed and results have shown a good agreement with those predicted by the proposed method.

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This paper discusses a vibration control algorithm for a tuned mass damper under non-stationary random disturbances. Selecting an appropriate set of passive mechanical parameters under a given feedback gain minimizes the energy requirement for the controller. This optimum selection is probabilistically obtained under stationary random process. It is also proved that the same optimum parameter selection minimizes the force requirement for the controller. The stochastically expected optimum parameter set is numerically evaluated in the time domain under non-stationary random excitations. The deterministic analyses ascertained that the control energy converges to zero as the time goes to infinity under any non-stationary random disturbances.

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Recently, low friction elastic sliding bearings are installed seismic isolated buildings with rubber bearings and dampers. Low friction elastic sliding bearings enable the base isolation system with longer natural period than the buildings with rubber bearings and dampers. A method to predict the response of this type of structures based energy balance theory is introduced in this paper. Natural period should be estimated energy spectrum and maximum deformation in consideration of effect of energy absorption and residual deformation. A design methodology of seismic isolated buildings with low friction elastic sliding bearings, that is based an energy balance, is presented.

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The attenuation relationships of peak ground velocity for horizontal and vertical components are inferred from the Kyoshin network strong motion data. The regression formulas derived for the both components explicitly include as arguments the focal depth and the sediment type in addition to the magnitude and the distance. The formulas well explain the attenuation of the peak ground velocities for shallow and deep earthquakes. Also, they show several interesting features of strong ground motions as follows. (1) Sediments amplify the horizontal component more largely than the vertical component and (2) Ratios of the peak ground acceleration to the peak ground velocity increase with the focal depth.

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The Purpose of this study is to grasp the possibility of using recycled aggregate concrete in the reinforced concrete structures. The seismic performance of the column members used recycled aggregate was compared with that of normal concrete members through the tests concerning flexural and shear. The parameters of the tests were three levels, of axial stress and two kinds of recycled aggregate concrete. From the test results, the failure mode can be predicted and the seismic performance of column members with recycled aggregate concrete were the same as those of the normal column members. Furthermore, it was found that the strengths of the column members with recycled aggregate concrete could be calculated as a safely side by previous strength equations.

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Macro-models for shear transfer in the reinforced concrete beam-column joints with headed anchorage of beam rebars are proposed. The models consist of the truss model and the strut model that fulfill the equilibrium of shear, moment and axial stresses. A criterion for the slip along the shear crack is also taken account to express the cone shaped splitting failure at the anchored portion. The results of the analysis varied concrete strength, amount of the transverse reinforcement and embedded length gave good agreement with the values of existing test results. The analytical results suggest that the tensile strength of the longitudinal bars in mid-depth of the column and the subjected axial load would contribute to the capacity of the joint shear transfer.

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For the design based on the performance, the evaluation method for the earthquake resistant performance of the reinforced concrete multi-shear walls is being developed. In this paper, the evaluation method for the flexural and shear crack width of the multi-story shear walls, which is originally developed using some .previous methods is described. The main characteristics of this method are following ; 1) the flexural crack width is calculated using the calculating result of the flexual deformation which is calculated by the proposed method. 2) the shear crack width is calculated using the calculating result of the shear deformation which is calculated by the proposed method. The calculated results by this method corresponded well to the experimental results.

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In this paper, cyclic load tests were performed, in order to investigate the restoring force characteristics of prestressed concrete beams in beam-column assemblies. The variables adopted in the tests were the size of the column, the amount of ordinary reinforcement in the beams, prestress and the location of the column in frame i. e. exterior or interior. Through these tests, it was found that the restoring force characteristics of prestressed concrete beams depended on the effect of the diameter of ordinary reinforcement in the beams and the locations of the columns in. frames. On the basis of the test results, a restoring force characteristics model was proposed in order to predict the hysteretic behavior of prestressed concrete beams in frames. The equivalent viscous damping ratio obtained from the model agreed with the test results.

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Many steel structures suffered damage at beam-to-column connections under the Northridge and Hyogo-ken Nanbu Earthquakes more than 8 years ago. After these earthquakes, a remarkable number of studies have been made on beam-to-column connections in U.S. and Japan. Nevertheless, in those studies, little attention has been paid to the point of repairing. The purpose of this study is to propose new ductile steel structure frame system, which realizes not only structural performances but also easy repairing after heavy earthquake. This system is based on bolted connections with split-tee. Main feature of this system is to limit plastic deformation to the splittee at bottom flange. To the contrary, the split-tee at top flange can be kept in elastic, because the center of rotation stays at the top flange of beam end.Consequently, when the structure using this system suffers compulsory deformation under the earthquake, the deformation concentrates on the split-tee at bottom flange. Finally, two series of static tests were conducted. First series are axial loading tests of the weak-web-split-tee elements, and second series are bending tests of beam-to-column connections having weak-web-split-tee. From the result of these tests, we verified that this system had efficient deformation capacity. In addition, the damaged part of this system would.be easy to repair or change to new one.

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Recently, Buckling-restrained-braces (BRB) has been widely used in steel building frames as seismic energy dissipation members. In these braces, connections are designed as rigid in rotation for in-plane direction, while joint rotation subjected to story drift being absorbed by slight angle at the end of plastic area of core plate in restrain tube. On contrary, for out-of-plane direction, it is sometimes difficult to design connection as rigid in rotation, and three-hinge instability including connections and core-end hinges is concerned. If the brace member including connections becomes instable, BRB cannot fulfill its function as energy dissipation devices. In this paper, out-of-plane stiffness of various types of gusset-plate connections including bolted joint system are tested, and required conditions of the connections for stable BRB's action are analyzed and discussed.

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With dynamic analysis, this paper attempted to illustrate the influence of structural models and input earthquakes on seismic performance evaluation of middle-and-low rise steel moment-resisting frames (SMRFs). Weak-columned SMRFs and artificial waves of an identical Fourier amplitude spectrum were selected to study herein. Analysis results showed that mass-spring models might evaluate as precisely as frame models, only if the relationship of shear force and story drift were setup equivalently. Moreover, the minimum acceleration rates of input earthquakes to have structural models reach the limit states such as elasticity and collapse would remain constant respectively. While the minimum acceleration rate necessary for the limit state of deterioration would significantly increase if the input earthquakes were changed from an epicentral type to an oceanic one.

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We studied a new restoring force model encompassing post-buckling for rational seismic design, and investigated a new analytical method for accurate calculation of dynamic behavior in earthquake using this model. Until now, we have calculated vibration responses from a static hysteresis loop relating to vibration characteristics (stiffness, damping) of the structure. However, restoring force tests clarified that the restoring force characteristics of silos are greatly influenced by not only amplitude of displacement but also response frequency. In this paper, we propose a new analytical model that .considers these vibration characteristics of silos, and verify the validity and accuracy of this new analytical method by shaking table tests. In the future, this new analytical model and method will enable calculation of more reliable structure's specific coefficients of silos.

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