Concrete fine powder that is residue after aggregates recycling of demolished concrete and acid water that is used for acid cleaning of rusted steel plates are the wastes thrown away as valueless substances. However, there is possibility for obtaining some valuable materials from the two wastes by applying chemical reaction between them, because the former is alkaline substance and the latter is acid solution. In this paper, the production process of obtaining valuable materials from the wastes was developed. Silica and calcium carbonate of more than 95% in purity could be successfully obtained through the developed process.

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The last study described that the shorter the period of standard curing, the smaller the development of static modulus of elasticity, even though the same compressive strength of high-strength concrete was obtained. Furthermore, the tendency was changed by sorts of cements under the standard curing. In this study, the static modulus of elasticity of high-strength concrete concerning core specimen from imitated concrete column and simple adiabatic curing specimen were investigated. In case standard curing specimen and adiabatic curing specimen were tested at the age of 13 weeks, the calculated value of static modulus of elasticity according to the New RC formula was almost the same as that of test result. However, in case core specimen from imitated concrete column was tested at the age of 13 weeks, the calculated value was smaller than the test result. Therefore, it is considered that the calculated value can be made more accurate when coefficients of cements, ages and specimens are added to the New RC formula.

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To build up a recyclable society, the environmental issue of concrete is approached comprehensively with a new technique using aggregate coating. The increase of concrete strength is achieved by 1.2 times using improved coating agent mixed properly with silica-fume and by-product powder. A similar effect is also affirmed even if applied to low-quality aggregate. A recycling performance shows that over 90% of aggregate can be recycled. In conclusion, the technique developed by this study is effective for the use of low-quality aggregate and the recycle of coarse aggregate as well as the solution of the environmental problem of concrete.

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In this study, a series of experiments on drying shrinkage of porous concrete was carried out to examine the influence of void ratio and water cement ratio on drying shrinkage characteristic. As a result, the drying shrinkage of porous concrete occurs much faster than that of normal concrete. It was also found out that the final amount of drying shrinkage of porous concrete is smaller than that of normal concrete. In addition, such tendency was more obvious when void ratio became bigger. Based on the experimental result, the prediction equation of drying shrinkage of porous concrete was inferred where the water cement ratio and void ratio are being considered. It was demonstrated that the curve of drying shrinkage of porous concrete can be well predicted by using the formula obtained.

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Polymer-cement waterproofing membrane is formed through hydration of cement and solidification of polymers, due to simultaneous water consumption by hydration to cement and water evaporation. Therefore, structures of membranes differ by mixing ratio of cement, polymer and particularly water content. In the study, polymer cement sheets were made by various ratios of the three components, and their structures were investigated through EPMA observation. Furthermore, a simulation model adopted water reduction by hydration and evaporation was developed. The simulated results were compared with observed ones and showed in approximately good accordance with the observed images. Finally structures of the polymer cement waterproofing membranes were discussed on the basis of the two results.

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Experiments to measure durability of resin floor coatings against caster-load and thermal-shock were done. Then, in several specimens, resin floor coatings were separated from slabs by loads. At that time, slab surfaces seemed to be broken. And, resin floor coatings were easily separated when surface strength of slab were low.
Finally the relation between the amount of loads until separation and surface strength of slab was quantitatively shown. This relation is regarded as one kind of barometers of slab surface quality, which is necessary to construct floors corresponding to quality required from users.

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In recent inland shallow earthquakes, pulse-like ground motions have been observed which subsequently caused severe damage to buildings. However, the response of buildings to pulse-like ground motions has not been sufficiently characterized yet. In this study, we investigate the effect of pulse-like ground motions on the design of structures and define the maximum response of an undamped singledegree-of-freedom (SDOF) system subjected to a sinusoidal pulse as a function of natural period. In addition, design response spectra for pulse-like ground motions are proposed.

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Many multi-crack models have been obtained from strong-motion records as the fault models for recent damaging earthquakes. However, these multi-crack models do not specify the total seismic moment or the magnitude of the earthquakes. Neither do they have a consistent physical basis between the slip and the stress drop, because no slip is assumed on the background of the fault for calculating the stress drop on the cracks while small amount of the slip actually exists on the background. Hence, we proposed a procedure for transforming the multi-crack models into the asperity models. The asperity models specify the seismic moment and have a consistent physical basis. They are also easy to apply to fault models for larger scenario earthquakes. As an example, we transformed the multi-crack model for the 2005 Fukuoka-Ken Seiho-Oki earthquake (M_J 7.0) into an asperity model, and then showed three different asperity models to predict strong motions for scenario earthquakes twice larger than the Fukuoka-Ken Seiho-Oki earthquake.

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Vertical motions have been required as input motions to important structures, such as nuclear power plants and base-isolation structures. However, empirical attenuation relations of vertical motions for big intraslab and interplate earthquakes in Japan had not been proposed yet. Therefore in this study we develop attenuation relations for estimating horizontal and vertical ground motions caused by these earthquakes. The relations are provided for peak ground acceleration (PGA), peak ground velocity, and 5% damped acceleration response spectrum (SA) for radial, transverse, and vertical components. In order to use the relations as input motions we obtain site coefficients at bedrock with different S-wave velocities. The attenuations of horizontal motions in this study obtained from records observed at the fore-arc are smaller than those in the previous ones. The ground motions for big intraslab and interplate earthquakes occurring at the Pacific plate are larger than those at the Philippine Sea plate at most cases. We find that the PGA and the SA in a short period range for intraslab earthquake are larger than those for interplate earthquakes at the same focal depth D and are roughly proportional to D^2/3.

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This study investigates characteristics of vertical dynamic responses of a seismically isolated 9-storey building in Kushiro City considering dynamic interaction of soil and pile-group foundation. Records during small earthquakes and their simulation analyses reveal that vertical motions at ground observatory sites 29m away from the building are contaminated by soil responses induced by vertical responses of the building, resulting in an apparent increase of magnification factors of vertical responses in resonant frequency. Effects of soil nonlinearity during the 2003 Off-Tokachi earthquake are small in terms of vertical response characteristics considering dynamic impedance. The static or maximum value of the real part in dynamic vertical soil spring is preferable as a constant soil spring used in the time-domain earthquake response analyses for safety-margin based structural design.

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This paper presents a new analytical model for predicting the behavior of elastomeric seismic isolation bearings subject to combined eccentric bending moments and shear deformation. The mechanical model consists of a series of axial springs at the top, mid-height and bottom of the isolator. The model can account for end rotations of the isolator, and the overall isolator rotational stiffness can include the influence of the variation of vertical load on the isolator and the imposed shear deformation. To identify the mechanical characteristics of isolators, static bending tests under various combinations of vertical load and shear deformation were performed. The results of analyses using the new model show very good agreement with experimental observations.

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The precast prestressed concrete frame with mild-press joints is considered to be a promising earthquake resistant structure on the reason that the structure behaves quasi-elastically under a wide range of story deformation due to elasticity of secondary PC cables applied to form the frame.
The flexible-stiff mixed structure which consists of elastic elements and stiff nonlinear elements has been recognized to develop most excellent structural performance under earthquakes.
In this paper, the possibility of concrete frames with PC mild-press joints are discussed through the estimate of its ultimate resistance to earthquakes based on the balance of energy between the seismic input energy and the absorbed energy by the frame.

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This paper proposes a method to create a shear beam model consisting of elements that represent hysteretic characteristics of the dampers, their support members/connections, and frames in a passively controlled muluti-story and multi-bay building. Four types of dampers, steel, oil, viscous, and viscoelastic dampers, are considered. The model enables efficient and practical time history analyses of the building subjected to ground motions. Degrees of freedom of the building are reduced to a few per floor, by conducting two or three static analyses. Then, a shear beam model of a few degrees of freedom per floor level is constructed by matching its behavior exactly with the building. The accuracy of the shear beam model is demonstrated via static analyses as well as dynamic analyses using a variety of ground motions.

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A new concept is presented for seismic isolation system using a compliant mechanism. Optimization approach is utilized for generating a truss structure that has specified equilibrium path, which can be achieved utilizing elastic deformation of a structure and geometrical nonlinearity. The truss structure can be used as a base-isolation system by assigning a path with gradually increasing load with respect to the displacement. Weighted sum of the error of the equilibrium path from the target path is minimized through optimization procedure. The compliant truss mechanism obtained from optimization is designed as the isolator model for the building frame. The effectiveness of our model of isolation system is validated by the result of time history analysis using recorded seismic motions.

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Recently, the environmental impact has been required to be explicitly taken into account in a life cycle design of building structures besides the initial economical efficiency, which has been ordinarily required up to the present days. Consequently, it is important not only to design the building structures so as to be safe as well as economical at the initial stage of completion of the building but also to pay attention and take into account the total behaviors of the designed and constructed building structures during all stages of their life cycles. The former paper of the authors has proposed the way to deal with the life cycle design of building structures with consideration of a hierarchy according to the ranks of building construction systems by using genetic algorithms as the optimization scheme with respect to both ecology and economy for evaluations. However, there are various uncertenties in a life cycle of building structures, therefore it is necessary to expand it to the life cycle evaluation that considered those uncertenties. In particular, the effect caused by earthquakes which occurs during the evaluation period should be investigated. Present paper proposes the way to realize the life cycle evaluation of building structures with consideration of seismic hazard, and investigate its effectiveness of Life Cycle Design considering seismic hazard through numerical examples.

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The present paper discuses on a dynamic seismic performance index of structure, _d I_s, and a dynamic ductility index, _d F, of a brace installed in the longitudinal direction of school sport halls. Based on the result of the elasto-plasitc dynamic analysis depending on various input levels, _d F and _d I_s are re-studied. As numerical parameters, a yield base shear coefficient of braces of substructure, C_y , and a capacity limit deformation of braces as well as hysteresis types are considered, and their effects on _d F and _d I_s are investigated.

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We, in this article, propose an estimation method of the partially compression of the timber damaged by termite perpendicular to the grain. The estimation method was composed of the three parts, easy ways for judging existence or nonexistence of termite, detailed percussive analysis for quantitative estimating lack of the area by termite, and mechanical model for estimating partially compression of the termite timber perpendicular to the grain using lack of the area. The easy ways are conventional ways using observation, sounding of stroke and resisting presser of the screw driver, but originally proposed the concept of 500 effective lengths. Detailed percussive analysis was originally proposed frequency analysis of sound wave. The mechanical model was originally proposed.

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A new type of moment resisting timber joint has been developed. The joint is made up of steel plates, bolts and cotters. The plates and the bolts are embedded with timber element of frame structure. By combining those elements with steel cotters, moment resisting joints can be constructed easily. Static loading tests of the joint have been performed, and results of the tests made it clear that the joint have rotational rigidity and strength required from constructing moment resisting joint.
In this report, three kinds of racking tests were performed to simulate the moment-rotational angle. “A tests” were prototypes, and “B tests” and “C tests” had each kinds of joint. The simulation results of moment-rotational angle curves by three kinds of tests agree with the prototype tests results.

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We, in this article, propose a manual calculation method for the skeleton curb of single bolted timber joint. The calculation method takes into account the edge distance, the end distance, and the slenderness ratio as the parameters. The validity of the proposed calculation method was confirmed by the experimental results, the edge distance of 1d, 2d, 4d, 6d, 7d, the end distance of 1d, 2.5d, 4d, 7d, 10d, the slenderness ratio of 0.625 d, 3.75d, 7.5d, 10d.

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The purpose of this study is to establish the evaluation method of the structural performance of connection in moment resistance timber frame under combined stress of bending moment and shearing force.In order to make clear the problem,bending and shearing tests with several different shear span lengths were carried out.Moment capacity of the moment resistance timber frame connection was evaluated accurately by using the shear span length not from connection point of linear elements,but from center position of the shearing resistance at the connection to the inflection point.

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A new test method for wood splitting was invented, in that hydrostatic pressure is introduced into a circular hole of a wood plate until splitting fracture takes place. Water pressure is applied to the wall of the hole through a soft balloon made of rubber, which generates uniform radial compression on the circumferential wall without friction. The splitting occurred at the coordinate where the tangent of the circle is right-angled to the grain of the wood, which was observed in the all specimens of Japanese cedar and SPF. The stresses around the hole were analyzed by means of Ikeda's formula in consideration of orthotropic elasticity of the woods, which revealed that the stress distribution around the circular hole is nearly equal to that of an isotropic plate. The stress criteria of fracture by Norris, Tsai-Hill, and Hoffman were examined, which demonstrated that the Hoffman equation incorporating tensile and compressive strengths is most favorable to predict the splitting strength of the holed wood plates subjected to the interior pressure.

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In this study, the limit curve relating between energy absorption and maximum displacement is derived from cyclic loading test of wood shear walls. Time-history analysis is also conducted to evaluate safety of wood shear wall based on the limit curve. As the results, following conclusions are obtained:
1) Limit state derived from energy absorption and maximum displacement of wood shear wall is similar to that of steel members. That means limit state is determined by energy absorption index.
2) The state mentioning above is slightly different from types of shear wall. Characteristic of sheathed shear wall such as plywood shear wall is close to steel member but that of bracing shear wall is close to medium characteristic of steel and reinforced concrete member.
3) According to results of time history analysis, responses which are designed in accordance with minimum requirement of Japanese building standard law transcend the limit state during extremely big earthquakes such as JMA Kobe and JMA Kawaguchi.
4) Aftershock should be considered in seismic performance for shear walls which is sensitive to energy absorption.

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The configuration of the crack in a high-strength concrete whose strength exceeds 100 N/mm² is much smoother than that in normalstrength concrete, and results in a loss of shear-transfer ability across the crack. Tests were performed on RC columns having concrete strength of 40 to 120 N/mm², axial load ratios of 0.1 to 0.28, and shear reinforcement ratios of 0.39% to 0.78% in order to study the influence of crack configuration, axial load and shear reinforcement upon the hysteresis characteristics under a cyclic shear loading. With increasing in axial load and decreasing in shear reinforcement, the shear sliding in the smooth crack of high-strength concrete increases and the solidity as a RC member is detracted. As a result, the hysteresis curves of high strength concrete columns with high axial load and little shear reinforcement showed an asymmetric response between positive and negative loading due to the large slippage in a shear crack. FEM analyses have been also carried out to examine the effect of the coefficient of friction when closing shear cracks.

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This paper describes an experimental study on the seismic performance of reinforced concrete shear walls. A series of structural tests was conducted using several types of shear wall specimens: one normal and three specific specimens. One of specific specimens was designed to measure internal forces on the critical section, which identified a structural weak point in this kind of structure. Based on the result, partial strengthening was applied to other specific specimens. Steel jacketing applied only to the structural weak point significantly improved the seismic performance, in particular ductility, compared to the normal specimen.

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The seismic response of three-story one-third-scale steel frames with columns allowed to uplift is evaluated and compared with that of fixed-base frames by three-dimensional shaking table tests. The test frames were retested using four different frame conditions: uplift-base and fixed-base frames; plan symmetric and asymmetric frames. The results are: 1) While the column uplift displacements of the uplift frames is increased by the vertical component of the input motion, the horizontal response values such as the roof drifts and base shears are not affected by that; 2) The difference of the roof floor rotations between the symmetric and asymmetric uplift frames are not increased in spite of the increase of the input motion intensity; 3) The base shears of the uplift frames are effectively reduced from those of the fixed-base frames; and, 4) The deformation of the uplift frames excluding the rocking component is nearly equal to or smaller than the elastic response value of the fixed-base frames.

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This paper showed the fatigue strength of load-carrying type and non load-carrying type fillet welded joints used SUS304A austenitic stainless steel, especially fatigue strength of corroded welded joint by salty environment.
The main results of fatigue tests were as follows:(1)The 2x106 fatigue strength of load-carrying type fillet welded joints were 64MPa for non-corroded specimens and 61MPa for corroded ones respectively, however over 100MPa stress ranges, fatigue strength of the latter were lower than those of the former. (2) The 2x106 fatigue strength of non load-carrying type fillet welded joints were 101MPa for non-corroded specimens and 67MPa for corroded ones respectively. (3) The deterioration of fatigue strength of corrode specimens were caused by stress corrosion cracks which occurred in the heat-affected-zone by salty environment and residual stress of welding.

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