Carbonation processes of cementitious concrete through burnt clay ceramic face materials were examined experimentally, and a predictive equation is proposed for evaluating the controlling effects on carbonation in this paper. Four levels in compressive strength of ceramics and two types of cementitious materials of both concrete and mortar were used as face materials with various thickness in this experiments. As a result, the predictive equation is clarified to be effective in case of ceramics and ready carbonated cementitious materials by an amendment to the original one called "time equivalent law" as well as in case of cementitious face materials.

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This paper is intended to study the mixing proportions of high bending strength mortars which have been developed recently and have been reported on this Transaction of AIJ No.492, 1997. 2. On this paper, the effects of the percentage of silica-fume, water binder ratio, sand binder ratio and the gain size of the sand were studied in order to grow up the bending strength of mortar. And the characteristics of these mortars were clarified, such as young's modulus, shrinkage, absorption, shockproof and fireproof properties.

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The original concrete to be used for the production of recycled aggregate is basically composed of the original aggregate and the original mortar, and, if the original aggregate has sound properties, the quality of the recycled aggregate depends on the property of the original mortar to a large extent. In addition, it is said that the degree of deterioration in the quality of the recycled fine aggregate is larger than that of the recycled coarse aggregate. Therefore, when the recycled fine aggregate or the concrete prepared using it is applied to the structural concrete, it becomes imperative to make a proper estimation of the effects of the properties of the original mortar as to their qualities prior to setting various mix design conditions. From this point of view, this paper presents a series of experiments which analyze recycled fine aggregate and recycled aggregate concrete as given below. 1. 12 types of original concrete were prepared using 3 types of original aggregate having different strengths, shapes and surface characteristics, and changing the water-cement ratio of the original mortar in 4 levels of 35%, 45%, 55% and 65%, respectively. Then, 16 types ofrecycled fine aggregate were made by manufacturing the prepared original concrete using 2 types of crushing methods. 2. The amounts of the original mortar contained in 16 types of recycled fine aggregate were estimated, and the tests on their various physical properties were carried out to clarify the relationship between them. 3. From among the above-mentioned 16 types of recycled fine aggregate, 6 types, which were made using the same type of original aggregate and the original mortar of different strengths, and by different methods to crush the original concrete, were selected. Using these 6 types of recycled fine aggregate, 48 types of recycled concrete having a different replacement ratio of recycled fine aggregate and a different water-cement ratio of concrete were produced to investigate the effects of the amount of the original mortar contained in each recycled fine aggregate and its properties on the quality of the recycled aggregate concrete. Much valuable information regarding useful results pertaining to the mix design of the recycled aggregate concrete to be produced using the recycled fine aggregate was obtained through these experiments and the analysis described above.

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In order to propose a method for predicting extruding pressure under extrusion moulding of cementitious components, mortars with various water content ratios and two kinds of fiber additives were extruded by extruders with different barrel diameters using various kinds of die opening geometries including the alternation of width, thickness and hollow ratio. It was verified that the effective thickness law was available, because the unique relationships between extruding pressure and effective thickness, which meant the transformation grade of mixtures, were obtained. Based on the law and plastic processing one, the comprehensive flow for predicting extruding pressure only through a single shear test was proposed.

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Deterioration with years in service of corrugated asbestos cement sheet (slate) is investigated experimentally. This material is widely used for roofing of factories. The present paper provides the properties of the slate being used for up to 35 years. Following experimental items are discussed, based on the experimental data. 1. Appearance changes : thickness, cross sectional density, interlayer segregation 2. Change in water absorption 3. Change in chemical property : pH, chemical composition 4. Change in mechanical property : flexural strength, Charpy impact value From the obtained experimental data, it is assumed that the flexural strength of the slate almost constantly decreases with years in service. Such tendency coincides with the fact reported by users, while that can not be predicted from the experimental data reported earlier.

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The buildings of a thermal power plant are generally supported by a large number of piles. When conducting a dynamic analysis of such buildings, the dynamic interaction system of a pile groupshould be evaluated. In this paper, the interaction system is proposed for the responses of the thermal power plant buildings subjected to earthquake excitation. The system is based on the simplified methods currently proposed by the authors, for the impedances of a pile group. The results of the analysis show that the interaction system is practical for the dynamic analysis of a building supported on a large number of piles.

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Non-stationary behaviors of inelastic structures during an earthquake are influenced by the characteristics of ground motions in frequency domain as well as in time domain. Wavelet transformation seems to be a powerful tool to translate time-sequence data into spectral information in a frequency-time plane. Thus, the application of wavelet inverse transformation may be feasible to make pseudo-earthquake motions having particular properties designated in both domains of frequency and time. In this paper, pseudo earthquake waves are generated on the condition that Fourier amplitude spectrum, energy input rate and occurrence time of predominant wave are given. It was found that these three parameters can be well controlled in the simulated waves by wavelet inverse transformation.

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After the 1995 Kobe earthquake, review of the intensity level of design earthquake motion has been often discussed. In order to provide the basic data for the discussion, this paper examines the occurrence rate of the destructive ground motion based on the case histories of damage earthquakes in Japan. The isoseismal maps of the earthquakes which caused the destructive motion of the J.M.A. seismic intensity 6 or 7 are collected. The characteristics of the earthquakes and the effect of surface geology on the isoseismal maps are discussed to derive the factors which cause the destructive motion.

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We have revised the distribution of the peak ground velocities (PGV) in the Hanshin area during the 1995 Hyogo-ken Nanbu earthquake. The original PGV distribution was based on only the damage of residential houses, but the damage of the other types of buildings is also considered in the revision. In addition, we have refined the resolution of PGV in many cho whose area is broad. Evaluated PGV distribution has good correspondence with observed records and evaluated ground motions in the main shock except for the liquefied area like reclaimed land or the cho in which the PGV level drastically changes. On the other hand, the PGV in Nishinomiya city is not less than 60% of that in the Kobe city.

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In this paper, a numerical calculation method in order to perform effectively shape analysis and optimization of structure is proposed. The procedure is based on an iterative calculation process known as the Cross method for indeterminate rigid-framed structural analysis or the relaxation method for pin-jointed frameworks. First of all, a given area in analysis is divided into partial regions and an elemental coefficient matrix is derived with the conventional finite element technique. Instead of solving the finite element equation of the overall structural system, the finite element equation in some neighborhood at the nodal point is only required. The procedure consists of a calculation for converting mechanical behavior on one node in the neighborhood into the influential forces on the adjacent node and repeats this manipulation in all the area. To make sure of availability and efficiency, this method is applied to forward analyses, both optimizations and a shape analysis of truss structure. All results are good in any case. The proposed method can be applied to any model of which a finite element method can be applicable.

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In Japan, to raise the reliability of the evaluation method on remaining tensile force in tendons of pre-stressed concrete containment vessels (PCCV) under long-term behavior, an evaluation method considering the redistribution effects by tensile force is proposed. Results from the proposed theoretical formula of friction considering thermal expansion and those of the past thermal experiment were compared. The proposed theoretical formula explains the experiment results on both the tensile strain distribution in the tendon, and temperature - strain relations.

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An aluminum single layered reticular dome is one of the most efficient structures because of the characteristics of a low specific gravity, a high strength to weight ratio and because of the possibility of high quality manufacturing. Such a reticular dome has a high in-plane stiffness through membrane actions which can make the structures thin and light. On the contrary such a thin shell-like dome is subjected to buckling and this bucking gives rise to an essential problem in structural design. The bending stiffness in connections of such domes is already recognized as one of the key factors for prevention of buckling. The present paper investigates the structural characteristics of ball type joints which are to be utilized to connect one members to another ones in the aluminum reticular dome. The first part of the paper concerns beam bending tests, through which the bending stiffness and strength were obtained, the second part compares the experimental results with the simulated ones, and the third part discusses an estimation method to calculate the bending stiffness and strength for designing such an aluminum reticular dome.

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Static load responses of a 4m span double-layer tensegrity grid which involves 13 simplexes have been investigated. The grid was easily assembled and properly prestressed. The overall load response corresponded with nonlinear analysis results with small discrepancies. Linear analysis, however, may considerably underestimate member forces though it predicts displacements quite well. The failure of the connection part did not lead to an unstable structure, thus some redundancy of the grid was observed. The experiment can assure the feasibility of the proposed grid in small-span application fields.

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Membrane structures keep their shapes only by in-plane stresses and, therefore, when the shapes of membrane structures are determined, minimal surfaces are often adopted as the original surfaces in the design process of membrane structures, because the shapes of the minimal surfaces completely coincide with those of the equally tensioned surfaces which are supposed to be the ideal original surfaces for this kind of structures. In the practical analysis of the minimal surfaces, Newton-Raphson method is generally adopted as the nonlinear numerical calculation method. However, the converged solutions can not be always obtained by using Newton-Raphson method, especially in the case where each nodal point has three degrees-of-freedom. In the present paper, in order to enable us to analyze the minimal surfaces even any conditions, SQP(Sequential Quadratic Programming) method is newly adopted as the nonlinear calculation method and the characteristic of the convergence of this problem is discussed.

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In recent years, extensive experimental studies have been carried out to establish a rational structural design method for reinforced concrete structures against local damage caused by the impact of various external projectiles. Through these techniques, several techniques for improving the impact resistance of reinforced concrete plates have been proposed. Of these techniques, attaching a steel liner on the rear face of the plates is considered to be one of the most effective methods for improving the impact resistance of reinforced concrete plates. In this paper, the predicting method of local damage to reinforced concrete plates with a steel liner caused by the impact of projectiles is studied. To evaluate quantitatively the effect of a steel liner in preventing local damage, the existing formulas are employed conveniently and the prediction of the proposed formulas is verified by analytical results using the Discrete Element Method and experimental results.

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In order to increase ductility of R/C framed shear walls, the reinforcing method to confine the end of peripheral columns in square steel tubes and also to arrange truss type ties in wall panels are proposed. In this paper, the experimental results of compressive loading tests of wall panel elements and lateral loading tests under a constant axial load of shear walls reinforced by this method are described. The experiments conclude that the steel tube and truss type ties increased the ductility of shear walls even if the margin of the lateral load carrying capacity due to shear failure to the capacity due to flexural yielding was narrow.

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The objective of this study is to clarify the influence of the slenderness ratio and bracing stiffness and le/lc on the strength and bracing forces of the compression members with two lateral bracings by using numerical analysis. The results are summarized as follows: 1) When le/lc=1.0 or λ^^-〓1.0, the maximum strength is close NcR as the bracing stiffness increases, and when le/lc<1.0 and λ^^->1.0, it exceeds NcR, where le is the unbraced length between the supporting and bracing points, lc is the unbraced length between the bracing points, λ^^- is the slenderness ratio with a buckling length of lc, and NcR is the Euler load with a buckling length of lc. 2) The bracing force is constant regardless of bracing stiffness if the bracing stiffness is sufficiently in size. When le/l=1.0, it is 0.6% of the maximum strength regardless of λ^^-. When le/lc<1.0, it increases as λ^^- increases and is more than 0.6%.

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Previously, the authors have studied and clarified the theoretical conditions for realizing a friction coefficient of over 1.2 for high-strength bolted joints. To meet the conditions, HF-splice-plates with sawtooth shaped projections on the friction surfaces, large hardness and high tensile strength, have been developed. In this paper, the high-strength bolted joints using the HF-splice-plates are examined experimentally. First, standard slip tests are carried out and the results show that a slip coefficient of over 0.9 is realized even when a thickness gap of 1.0 mm between connected plates exists in the joint due to the construction tolerance. Second, cycle loading tests are conducted and it shows an interesting fact that the slip coefficient slightly increases after 10 cycle loading with a constant maximum load corresponding to a slip coefficient of 0.9 is given. Finally, buckling tests of HF-splice-plates are carried out and the results shows that the buckling strength of HF-splice-plates can be calculated based on the AIJ regulation.

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The authors propose the elasto-plastic frame analysis on steel frames with composite beams, focusing on the structural non-linearity of headed studs. The structural non-linearity was experimentally investigated while the slip rigidity was theoretically calculated. This analytical method showed a good agreement with the results of tests on steel frames with continuously spanned or long-spanned composite beams, leading to the fact that the effective width of slab on long-spanned beams should be taken shorter than designed, while the one for short-spanned beams may be taken as the same as designed.

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Column base is one of the most important element of steel structures. It is important to investigate the influence of elasto-plastic behavior of column bases on the ultimate earthquake resistance of steel frames. In this paper, a series of inelastic response analysis of multi-story steel frames with exposed type column bases, especially weak anchor bolt type column bases, were carried out. From the analytical results, following conclusions were obtained. 1)The intensity of the damage concentration at the structural element of the 1st story in the frames with exposed type column bases were much less than that of the frames with pin type column bases and the frames with fixed column bases. 2)Ultimate earthquake resistance of the frames with exposed type column bases were similar to that of the frames with pin type column bases. 3)If columns of the frames were ductile, ultimate earthquake resistance of the frames with exposed type column bases were similar to or a little better than that of the frames with fixed column bases. If columns of the frames were not ductile, ultimate earthquake resistance of the frames with exposed type column bases were much better than that of the frames with fixed column bases. 4)Energy absorbing capacity of the exposed type column bases were much less than other structural elements.

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When a steel frame is subjected to horizontal force due to earthquake, high shear force is developed in the beam-to-column joint panel. Many studies to investigate the strength and deformation of joint panel were carried out. In this paper, the shear force loading tests for joint panel and for cruciform subassemblage of rectangular and circular hollow section are reported. As the main experimental parameter of these tests, axial force ratio and loading direction are selected. The results are summarized as follows. The hysteretic characteristics of joint panel are different from the steel grade and how to make of rectangular and circular hollow sections. Axial force leads to reduction of the strength and the increase of axial displacement. The hystereses of joint panel in cruciform subassemblages are similar with those of specimens of shear loading test. And the strength of panels agrees with those of specimens of shear loading test.

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We carried out the experiment of the brace members made of the expansive concrete filled steel pipe with a flat bar in center. The results of this experiment may be summarized as follows: 1) the share ratio between the flat bar and the steel pipe of tensile force due to chemical prestress is almost constant and independent on a variation in the cross section of the flat bar, 2) The apparent tensile strength of the concrete in the brace is mostly dependent on chemical prestress, 3) The real bond strength betweeen the flat bar and the concrete is about 75〜100kgf/cm2.

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This paper focuses on the total earthquake damage suffered during a building lifetime and evaluates the overall building performance. The ratio of damage cost is obtainable by setting a function of the response of the building which affects damage. (1) The damage cost ratio of structural members is considered to depend on the amount of energy absorbed by the members. (2) The damage cost ratio to nonstructural members is assumed to depend on story deformation angles. (3) The damage cost ratio to the building contents is defined by the minimum response acceleration necessary to topple them and the response velocity.

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Previously, we have conducted measurements of heat flux and temperature distribution of the H-shape beam installed beneath a ceiling and exposed to a localized fire source. From the results of the experiment, heat flux distribution on every part of the beam was formulated, In this paper, the temperature distributions were computed by the finite different method using experimental heat flux data and compared with results of the experiments to evaluate the applicability of the analytical technique. As a result, we confirmed that thermal analysis by the model is effective within error of 25%.

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The paper written by Drs. Motosaka and Nagano deals with the seismic ground motion amplification due to the edge structure in Kobe, actually at Nada ward, with the special reference to the heavily damaged zone in Kobe. The main conclusion of the paper is essentially the same as of the discussor that has already been published and so he need not to object to it. However, this paper contains several statements that would lead to serious misunderstanding by general readers. The primary purpose of this discussion is to prevent readers from such misunderstanding.

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The authors thank Dr. Hiroshi Kawase for his discussion and the answers are as follows. (1) The 'focusing effect' used in a wide meaning in the original paper has the same meaning as the 'edge effect'. Although the ground motion amplification near the basin edge is due to the superposition of the directly propagating body wave and the defracted surface waves rather than the refracted body wave, the authors used the terminology 'focusing effect', because the superposition at a basin edge lead to almost the same amplification characteristics at the concave underground structure where the terminology is commonly accepted, as example analyses are shown in this answer. (2) Although the references which the discusser suggested should have been added in the reviewing process, the referred literature are selected based on the earlier stage research activities taking account of priority of the idea focused on the effect of deep irregular underground structure with exception of some references indicated in the reviewing stage. (3) As for the relation between PGA distribution and damage distribution, the authors referred the damage distribution which is best coincident with the analytically obtained PGA distribution among the some other damage distributions near the analyzed section. Although the PGA may not be good index to discuss structural damage, the calculated PGA distribution is coincidence well with the damage distribution. This reason seems to be that the PGAs are determined from the relatively longer period contents than 0.5s in Kobe case.

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