In recent years, the control of setting time of concrete has become significant due to the development of various kinds of concrete. In general, JIS 6204 specifies the test method of setting time of mortar mixtures by penetration resistance. However, since measuring the penetration resistance in the case of long setting time requires considerably a great deal of complicated work, the simple way to predict the setting time could be advantageous in quality control at the concrete industry. This paper proposes an evaluation method of setting time of mortar mixtures by mortar thermocouple method comparing the test results by a mortar thermocouple method with penetration resistance using the sample mortars containing the diverse kinds of admixtures and three different aggregates. A mortar thermocouple method could evaluate the setting time by automatically measuring a thermal hysteresis.

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In this study, the rheological properties of fresh mortar and concrete were investigated experimentally by shear box test. The pore water pressure in fresh mortar and concrete was measured as an influence factor of rheological properties of fresh concrete. The cohesion and the coefficient of dynamic internal friction were represented from pore water pressure and shear stress measured in the experiment. As the result, it was clarified that the rheological properties is affected by the pore water pressure in fresh mortar and concrete. Moreover, the correcting method of shear stress in case of shear box test was obtained, and the cohesion and the coefficient of dynamic internal friction were quantified.

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The strength and hardness of concrete slab surface is considered significantly affected by bleeding of concrete. It has been reported that vacuum processing is quite effective to obtain high density of concrete. The method, however, has not been successfully used for the concrete work in the field of building construction, compared with that of civil engineering works in Japan. In the present study, as the sequence of the earlier experiment, two series of experiments have been carried out in order to examine the effect of mesh size of a filter mat and vacuum pressure ratio. As a result, the internal strength distribution of concrete slab gets to be more preferable as the mesh size becomes smaller and vacuum pressure ratio higher. Further, discussion has been conducted, based on the experimental results including the earlier ones, in order to find more reasonable and effective way in the application of the proposed vacuum processing method.

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Further spread of the use of high strength concretes for building construction requires knowledge of the influence of the physical properties of coarse aggregates on the compressive strength of high strength concretes. In this study, the compressive strengths of concretes with different types of coarse aggregate were determined and the relation between the concrete strength and the physical properties of the coarse aggregates used was analyzed. The results indicate that coarse aggregates with high compressive strength and small Young's modulus are best suited for use in high strength concrete.

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The sheets which consist of portlandite and sepiolite with different mixing ratio were prepared, and examined its characterization and water vapor adsorption/desorption characteristics. As a result of this study, the following was concluded. (1) The carbonation treatment influenced only in portlandite, and it was not influenced at all in sepiolite. (2) Carbonation progress of portlandite is related to the porosity of the sheet, and the difference between internal diffusion speed of carbon dioxide is considered. (3) The change of porosity of the sheet by carbonation hardly could be recognized. (4) The sheet with much content of sepiolite had large specific surface area, and it was excellent in the water vapor adsorption/desorption feature. (5) The bending strength of the sheet depended on the content of portlandite.

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Durability of wood translucent coating materials has been evaluated through an outdoor exposure test, an open-flame carbon-arc type accelerated weathering test, and a biological degradation test. These tests were conducted to clarify a durability level of wood translucent coating materials and to clarify which factor was predominant for outdoor deterioration between weathering deterioration and biological degradation. The results obtained can be summarized as follows: 1) It is considered that durability level of the translucent wood coating materials is not so high as emulsion paints and alkyd type of ready mixed paints. However, the translucent wood coating materials showed rather uniform deteriorated appearance compared with emulsion paints and alkyd type of ready mixed paints. It is considered that such uniform deterioration states are desirable for repair coating. 2) The results of the open-flame carbon-arc type accelerated weathering test are consistent with those of the outdoor exposure test. On the other hand, the results of the biological degradation test are not consistent with those of the outdoor exposure test. Therefore, it is considered that weathering deterioration is more predominant than biological degradation for outdoor deterioration of the wood translucent coating materials.

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1. It was implied that the device for stains on polymeric floor materials might be suitable for accelerating the stains of wallpaper. 2. Some specifications of accelerating device for stains on wallpaper were selected, the applicability of the specification was examined, and the most suitable specification was decided. 3. The evaluation scale for the stains on wallpaper was created through a sensory test. 4. Based on the relation between the evaluation scale and color deference, an index for evaluating stains on wallpaper was presented.

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This paper describes the results of full-scale measurements of wind pressures and wind forces on roof tiles. The objective building has a rectangular plan of 5.4mx4.8m and a ridge height 6.7m and has a gable roof. The results are as follows: 1) The mean pressures on the upper surfaces of the tiles were roughly the same as those on under surfaces over most areas of the roof. 2) The mean forces on the roof tiles were very small compared with the peak forces, so that their contributions to the peak forces were small. 3) The coherencies between the fluctuating pressures on upper surfaces and those on the under surfaces of the tiles were high in the low frequency region. 4) The coherencies between the fluctuating internal pressures on the roof tiles were higher than those of the fluctuating external pressures. A time series of internal pressures and wind forces on a tile was estimated from the time series of the external pressures obtained from the measurements. The estimated time series of wind force showed good agreement with that obtained from the measurements.

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Although a new law was enacted in 1995 to promote retrofit of old buildings to improve their seismic strength, the number of buildings already treated is very limited. In this paper, in order to improve this situation, fragility analysis systems that can quickly evaluate the seismic strength of a building are studied. First, the existing systems were evaluated in the view point of their model structures. The exiting fragility analysis were found to be classified into two, empirical systems and analytical systems. The empirical systems are appropriate to estimate the fragility of a group of buildings in a city or a region. However, they can not be applied to an individual building directly. The analytical systems may be applicable to individual buildings, if certain information is available. Based on this observation, a new fragility analysis system based on the analytical system, HAZUS, is proposed in this paper. As the model structures of HAZUS are not suitable for Japanese buildings, several revisions were made. Moreover, it provided an easy way for relative comparison of the strength of buildings. Thus, the prioritization of retrofits can be decided accordingly. The proposed system was applied to school buildings that usually employ standardized design practice. Using the proposed system, we may be able to reduce the cost of decision making for retrofits of a group of buildings such as school buildings.

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This study proposes an optimal selection method for base-isolation devices using a genetic algorithm which considers the superstructure's response. When the superstructure's horizontal stiffness is relatively low, the superstructure cannot be treated as a rigid mass. Therefore, the superstructure is modeled as shear mode multi-mass system. Parameters in the genetic algorithm's evaluation functions are: A) eccentricity ratio, B) vertical load on each isolator, C) natural period, D) yield shear force coefficient of base isolation device,E) storey shear force coefficient and F)base isolation displacement. We employed two groups of parameters: (1) A-B-C-D, (2) A-B-E-F. We did time history response analyses with buildings designed by the proposed method. As a result of the analyses, the maximum peak accelerations of superstructure were suppressed using parameters group (2). Therefore the proposed method was effective in selecting base isolation devices.

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This paper presents the damping performance characteristics of Peripheral Restraining Lead Damper, which is a hysteretic type damper used for the seismic structural response control and consists of the lead plug and the projective bond plates pressed into the hole of hexahedron laminated rubbers. As a result of dynamic tests, the damping performance characteristics depend on the amount of cumulative hysteretic energy absorption, the environmental temperature, the excitation frequency, and the shear deformation specified. Considering these dependencies, the new analytical hysteresis model was presented, and it was confirmed that the model had enough accuracy from the engineering viewpoint to reproduce the experimental results.

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Recently, the seismic isolated building is recognized as the structure system having high reliability and performance under severe earthquake. And the response prediction method for the seismic isolated buildings with viscous damper based on energy balance theory is proposed by Akiyama. This method proposed by Akiyama adopts the same way as the design method for seismic resistant structures. In this method, it is assumed that the sum with vibration elastic energy of isolator and the plastic strain energy of damper is equal to a difference of input energy and damping energy of viscous damper. This paper is developed this method, and focused on the shear force of viscous damper supporting the earthquake force. The response prediction method is calculated as damping energy is included in the absorbing energy accumulated to structure. And optimum damping coefficient of viscous damper is calculated with the parameters of input energy and natural period. Then time history response analyses are carried out to verify the proposal method. Finally, summary of design method for the seismic isolated buildings with viscous damper is shown.

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Most of the passive control devices currently used for buildings can be categorized into a velocity-dependent (visco-elastic or viscous) device and a displacement-dependent (elasto-plastic or friction) device. A visco-elasto-plastic (VEP) damper that combines in series a visco-elasto device and a friction device shows better performance than either one of the devices. We have conducted dynamic testing of a frame structure having the VEP damper, and have confirmed proper functioning of the structure. A series of analyses were also conducted for this passive control system, by using a fractional time-derivative visco-elastic constitutive rule and a bilinear elasto-plastic constitutive rule, and the results appear to correlate remarkably well with the experiments. Simplified expressions are proposed for deformations of both devices of the damper, as well as effective stiffness and damping of the damper and structure.

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The use of flat-plate structures have increased because this type of structure can realize optimum and flexible space utilization. In the application of flat-plate structures, slab resonance should be an important consideration, because of potential problems such as incorrect operation of equipment in manufacturing facilities or occupant discomfort in residential structures. However there are few studies on the free vibration analysis of slabs within flat-plate structures. In this paper, the free vibration analyses of plates with columns resting on lateral, rotational and torsional elastic edge supports uniformly are carried out by use of the superposition method based on the Mindlin plate theory. In order to study the vibration properties of the plate, column size, plate aspect ratio and plate thickness ratio are set up as evaluation parameters.

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There exists the immune algorithm as a computational method in solving optimization problems. This algorithm imitating the immune mechanism in the mammal has a notable characteristic that is able to search a solution set with diversity in optimization problems. However, application of the immune algorithm to structural optimization problems is a few in the present stage. In this paper we would like to improve the conventional immune algorithm with the gene of binary number type to immune algorithm with the gene of a binary-coded type and a real-coded type in applying to structural optimization. The applicability and effectiveness of our immune algorithm is shown through numerical models on the minimum weight design and the topology specification of elastic truss structure. The obtained numerical results are compared with the results by the standard genetic algorithms and the real-coded genetic algorithms. Moreover, in our immune algorithms an efficient procedure on selection of four computation thresholds in order to generate a solution set with diversity is also proposed.

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This study is related to the mechanical behavior of cement-treated sands by the cement stabilization method. In this paper, the evaluation method of cyclic strength and the cyclic shear properties of cement-treated sands are investigated in detail by performing hollow cylindrical torsional shear tests. The following conclusions were obtained, (1) The addition of a small amount of cement improves significantly the cyclic shear properties of untreated sands. (2) Relations between the normalized cyclic stress 'τ_<cy>/qu' and the number of loading cycles 'N' almost indicate the tendency that 'τ_<cy>/qu' seems to converge in uniformity value where the degree of cementation exceeds a certain level. (3) The cyclic strength of cement-treated sands can be approximately evaluated from the unconfined compression strength 'qu', the effective mean principal stress 'σ'm', and the initial shear modulus 'G_<max>.'

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This paper presents a proportioning method for constitutive members of cylindrical latticed roofs under uniform vertical loading. The method can be applied to design member sections of long roofs as cylindrical shells. Member axial forces and bending moments for design are first obtained based on FEM linear elastic analysis together with FEM linear buckling analysis for estimating the generalized equivalent slenderness. And, second, the bending moments are amplified considering the interaction between axial force and bending moment. Member elasto-plastic buckling strength is defined based on the theory of column buckling strength curves using the generalized slenderness. To define the buckling strength of members parallel to the generatrix as well as along arch direction, buckling analysis for not only uniform lateral but also axial loading are applied. Finally, a series of FEM elasto-plastic analysis is conducted for cylindrical latticed roofs, which are provided based on the present proportioning method, and a confirmation about availability of the present proportioning method is firmly given.

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Mechanical properties, ultimate strength and Young's modulus, were measured in tensile, compressive and bending tests with small clear test specimens of used wood. Test specimens of Tsuga (Tsuga sieboldii Carr.) were obtained from a demolished wood structure of temple aged about 70, and Akamatsu (Pinus densiflora Sieb. et Zucc.) were obtained from two demolished wood structures of temple aged 115 and 255. In order to make the mechanical properties of new wood for comparison to those of used wood, a Monte Carlo simulation was developed using the data for new wood of 35 Japanese species. The simulation calculation was done to make the mechanical properties which had the same distribution form of density as that of used wood. The comparison of mechanical properties of used and simulated new wood is summarized as follows: The ultimate tensile strength (UTS) of all used wood decreased in comparison with new wood. The mechanical properties of Tsuga used wood increased except UTS. Young's moduli obtained from compressive tests decreased in used wood except Tsuga used wood. The difference between Akamatsu used wood and new wood was not significant in the ultimate strength obtained from compressive and bending tests. The failure mode was recognized to be brittle.

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This paper discusses the stress transfer mechanism of reinforced concrete hinge isolated beams in the edge parts where steel sleeves cover longitudinal steel bars of members. The stress of steel sleeves, and the stress and moments acting on concrete at edge parts of beams were theoretically investigated and compared with the test results. The results of theoretical investigation and the test results clearly proved the excellent structural performance of reinforced concrete hinge isolated beams; the truss mechanism worked at edge parts of beams where longitudinal steel bars were un-bonded, and significant damage such as severe cracks of concrete did not occur even in the large deformation range of members, because the bending moment acting on concrete at the hinge regions was fairly small due to the un-bonded longitudinal steel bars.

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In this paper, cyclic loading tests are conducted in order to certify the mechanical behaviors of the frame structures with PC Mild-Press-Joint. Two kinds of series specimens are prepared and experimented. Specimen BF Series was beam yield preceding type. Specimen JS Series suffered larger shear force in the joint panel. Both BF Series and JS Series were of two kinds, i.e. a partial frame using PC Mild-Press-Joint and RC-structured partial frame. The following conclusions were drawn from the study where partial frame experiments were conducted using prestressing strands and verification was obtained by comparison with RC frames. 1) The damage on P/C MILD-PRESS-JOINT frame is very small as compared with RC frame. 2) Shear crack strength of the joint panel cloud be evaluated by taking into account the column prestress and beam prestress. 3) Increase in shear strength of the joint by about 40% of the initial anchoring force can be expected for using the current specimens.

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The objects of this paper are to investigate the inelastic behavior, strength and deformation capacity of semi-rigid beam-to-column connections using top, seat and web angles. Based on the test data, the evaluation formulas for initial rotation stiffness, yield strength and the second stiffness is proposed. The relationships between the moment and rotational angle considering of the strain hardening of the angle member are estimated using the above evaluation formulas.

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The experiment on cumulative plastic deformation capacity of steel beams up to ductile fracture under variable ductile amplitude cyclic loading was carried out. Cumulative plastic deformation capacity by constant amplitude loading could be formulated by similitude law of prefracture hysteresis. That by variable amplitude loading could be formulated by similitude law and Miner's law. That was also influenced by the order of large and small amplitudes and by deviation of maximum amplitude from average amplitude. The limit point when strength was decreased to a specified value was defined. Cumulative deformation capacity up to the limit point could be formulated by similitude law and Miner's law.

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For the development of performance based design taking into consideration economic losses after earthquakes, the reparability limit should be clarified in order to avoid demolishing. In this paper, the reparability limits of steel structural buildings were investigated based on the actual data of repaired or demolished buildings which were damaged by Hyogoken-nanbu earthquake both from technical and economic points of view. The investigation provided the following results on the reparability limit: 1) overall residual drift angle was 1/110, 2) maximum residual inter-story drift angle was 1/71, 3) ratio of direct restoration cost was 0.86, and 4) ratio of indirect restoration cost was 0.40. Furthermore, based on the actual data, the relationship of residual drift angle and ratio of restoration cost was investigated and the reparability limits synthesizing technical and economic aspects were defined by overall residual drift angle and maximum residual inter-story drift angle as 1/200 and 1/90, respectively.

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The purpuse of this study is to clear the efficient of torisonal rigidity of flanges for elastic buckling strength of web plate under bending shear and axial force. The evaluation of buckling strength of plates under bending shear and axial force has already proposed, in case of simple-supported plates and clumped plate. However, web plates in real H-shaped member is not under simple-support or clumped, web plates are under a finited torisonal rigidity of flanges. Thus, it is necessary for better evaluaion of buckling strength that the effecient of this torisonal rigidity. So, in this paper, a buckling analysis of plate under bending-shear and axial force is performed, thinking the efficient of flange torisonal rigidity. This analysis is done with energy method. Then, the efficient of torisonal rigidity of flanges for elastic buckling strength of web plate under bending shear and axial force is cleared. And, new evaluation method is proposed. The accuracy of this new method is higher than that of the past method.

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The aim of this study is investigating the hysteresis behavior of structural steel subjected multi-axial loading. For this purpose, the loading equipment and cylindrical specimens were manufactured. The loading equipment provided various loading paths, such as uni-axial loading, simultaneous loading of axial force and torsion, and alternating axial force and torsion. Uniform multi-axial stresses were generated in the cross-section of cylindrical specimens. The stress-strain relations were measured and the hysteresis behavior was examined in term of effective stress-effective strain.

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A concrete-filled tubular truss CFT truss is a truss composed of parallel chord members made of CFTs. A multi-story frame using CFT truss girders might have an exellent seismic-resistant capacity, so that the CFT truss could have an exellent derformation capacity without any flexural buckling. In this study, mainly, two topics are discussed. One of two is the local use of CFT trusses at the end portions of girder where plastic derfomations are expected to happen. The local use of CFT trusses will save the weight of concrete and time of concrete casting. The other is the use of CFT truss girders in a multi-spanned frame. The derfomation capacity of a CFT truss is guaranteed unless the plastic elongation of chord members in tension are restrained. In a multi-spanned frame, it should be clear how much a chord member is restrained by the next beam. Additionaly, differences between low and high rise buildings with short or long spanned beams are disscussed.

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The discusser absolutely disagree with the evaluation described in the paper mentioned on the face about the followings. 1) The equation on shear strength of a stud bar 2) Interaction between axial force and shear strength of a stud bar 3) Bearing capacity of partially loaded concrete The discusser asks the authors to explain the arguments of the evaluation about the above mentioned three points.

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The authors thank Prof. Katsuki Takiguchi for discussion, and the answers are summarized as follows; 1) The deformation at un-bonded part of stud bars was estimated to be similar to a cantilever beam and shear stress was examined at the fixed end. 2) The concept of effective number of stud bars located in compression side was made only by technical assumption, and should be continued to investigate in the future. 3) The area contributing to bearing pressure was assumed to be able to enlarge to some extent, because the coefficient prescribed in "Standard for Structural Design and Construction of Prestressed Concrete Structures, AIJ, 2002" is a conservative value.

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