Extrusion characteristics of cementitious materials with a wide range of viscosity of visco additives were experimentally examined in comparison with standard cementitious materials which consists of ordinary Portland cement, silica sand, water, methylcellulose as visco additives and chrysotile as fiber ones. Operating points and unit conveying rate in the cases of high viscosity, low one and low contents were lower than medium one. Single shear characteristics, namely cohesion and internal friction coefficient, are clarified to be available for evaluating extrusion characteristics before extrusion moulding in various cases of cementitious materials with various viscosity of visco additive.

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The optimizations of substance and their compositions is dealt with in this paper especially for used on the improving effects on ductility of cemetitious components by means of using hydrophilically treated polypropylene fibers. The following items are clarified; 1) The greater water content ratio became, the smaller extruding pressure became and the greater extruding velocity became. 2) Relationships between conveying rate per revolution and extruding pressure gave a unique curve independent of kinds and geometries of fibers, which were only dependent on the machinery condition. 3) The longer and the thin fiber became, the greater extruding pressure generally became. 4) Hydrophilic Porypropylene fiber can reduce extruding pressure in the range of low water cement ratio, and gave similar velocity as Chrysotile. 5) The most appropriate geometries were 2d×3mm in this experiment from the viewpoints of increasing firstly cracked and ultimate one, density, and reducing extruding pressure.

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In this study, the prediction equation of drying shrinkage of concrete is obtained with two-phase composite model as aggregate and matrix. In order to obtain the input values for this prediction equation easily, the experimental formula of drying shrinkage and young's modulus of cement paste are obtained, and the estimation method of young's modulus of aggregate are proposed with easy test using cement paste, mortar and concrete. According to the experimental results, this equation can predict the drying shrinkage at any age in error by less than about 100μ.

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This report describes an experiment on the mechanical properties of high-strength concrete (water cement ratio from 20% to 50%) tested during high-temperature heating (heating temperature from 100℃ to 600℃), and discusses the results. The following conclusions were obtained. 1) The compressive strength of the concrete tested during heating fell as the temperatue incrased from 100℃ to 200℃, recovered from 300℃ to 400℃, and fell again over 400℃. This shows a complicated change in concrete compressive strength. 2) High-strength concrete tested during high-temperature heating had higher compressive strength and Young's modulus than normal strength concrete under the same conditions.

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In this study, numerical analyses concerning the propagation of electromagnetic waves in concrete were carried out for examining the effects of various factors and for improving the accuracy of inspection for inclusions embedded in concrete by radar, by using finite-difference time-domain (FDTD) method. As the results, the validity of applying FDTD method to the radar analysis by electromagnetic waves was confirmed, and a treatment method for easy judgement of the location of reinforcing bars was suggested by the numerical results concerning the propagation property of reflected electromagnetic wave against reinforcing bars.

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This study proposes an unique technique for improving qualities of concrete with recycled concrete coarse aggregate; a decompression and rapid release (DC-RR). The DC-RR procedure is applied after normal mixing of concrete with recycled aggregate. Through the DC-RR procedure, the micro structure of interfacial transition zones between recycled aggregate and new matrix mortar are estimated to be dramatically improved. In this paper, experimental studies are described on the effectiveness of the DC-RR procedure on some of the mechanical and physical properties of concrete with recycled concrete coarse aggregate. It was found that, by applying the DC-RR procedure, compressive strength of the concrete can be increased by about 15%, creep and carbonation depth can be reduced by about 20%.

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To establish the evaluation method for removability of graffiti on the building materials, following two investigations was carried out. One is, the actual condition of graffiti was investigated at 20 parks in Funabashi-city. Other one is, the effects of test conditions were examined on the removability of graffiti. In the parks, the graffiti were almost colored with black, blue, red and white of paint and marking pen. The graffiti was written on test material in paint or a marking-pen. The graffiti on test materials was removed by rubbing with a dry cloth while spraying ethyl alcohol. The removability is affected by the type of paint, color, keeping period after painting, and kind of detergent.

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The purpose of this study is to present the rapid evaluation method of the permanent indentation of floor finishing materials caused by concentrated static load of furniture etc.. First, we developed the apparatus which was able to aply the concentrated load on floor finishing materials and also to measure the permanent indentation. Next, by means of the apparatus, we surveyed the permanent indentation of many kinds of floor finishing materials. Then, we found out physical value which was measured rapidly and corresponded to the permanent indentation. As a result, we presented the rapid evaluation method of the permanent indentation.

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The objective of this study is to establish an evaluation method for the state of stains by rubbing by sole of footwear on inner walls. On the basis of the survey of the state of stains, the typical kinds of human rubbing matter are selected. To construct psychological scale, the sensory test is conducted. The color difference between stained and unstained material is measured. The relation between psychological scale and the color difference is presented as the evaluation index. On the basis of load and stains when some examinees practice the rubbing motions, one motion is selected as a representative.

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This paper discusses the quasi-static wind load effect combinations to be considered in structural design of low-rise buildings. Various load effect combinations, e.g. across-wind base shear and torsional base moment accompanied by maximum along-wind base shear, are analyzed and discussed. Then it examines actual wind pressure distributions causing the maximum quasi-static stresses in structural frames. They are compared with Kasperski's LRC formula and the quasi-steady pressure distributions.

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The current research concerning reliability of structures and structural systems has been mostly concentrated on reliability analysis ignoring the influence of deteriorating resistance due to load history or aging, because of complexity of probabilistic treatment of its effect. In this paper, the analysis method to assess reliability of structural systems with deteriorating resistance due to load history under repeated random loads is presented, by introducing the probability density function of the residual resistance of survived structural systems where the deterioration effect is considered at every structural element. Finally, the effect of deteriorating resistance on reliability is discussed with numerical examples.

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Modelling of peak factor for non-Gaussian wind pressure fluctuation is proposed. A translation process with polynomials is applied to model wind pressure fluctuation. According to the proposed model, peak factors for non-Gaussian process can be easily formulated with higher moment parameters. The comparisons with previous works are illustrated to show the difference between proposed method and previous ones.

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The goal of this study is to achieve a better understanding of dynamic nonlinear behaviors of soil-pile-structure interaction systems under severe ground motions and to confirm applicability of a nonlinear response analysis method. We conducted vibration tests of a pile-supported structure in a liquefiable sand deposit at a large-scale mining site. This paper shows the simulation analyses of the pile-structure responses. A beam-interaction spring model was used to simulate the three-dimensional dynamic behavior of the system. Analyses results for dynamic responses of the super-structure, pile bending moments and pile axial forces during liquefaction were good agreement with the test results. It is clarified that the analysis model can properly evaluate the responses of the pile-structure system in the liquefiable sand deposits.

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A framework for probabilistic estimation of structural damages, which includes identifying its existence, location, and severity, through system identification of a building utilizing the observed vibration data before and after an severe earthquake occurs is presented in this paper. The proposed method is applied to the data obtained by the response analysis of a numerical model, which shows that the method can precisely estimate the stiffness reduction ratio and the damage probability of each story. Furthermore, the reliability of the estimated values are evaluated quantitatively and are reflected in the damage probability. The effect of the combination of the sensor locations and the number of modes used on the estimation result is also investigated.

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To clarify the problem on the existence of many shear coefficients for Timoshenko's beam theory, the simple beam of rectangular section subjected to surface loading is analyzed by the two-dimensional elastic theory. The main results are as follows. The deflection expressed in terms of square of span is composed of not only shear deformation but also the other two deflections, which are different modes than that of shear excepting simple beams, i.e., bending deformation caused by perpendicular stress and deflection by perpendicular strain based on bending stress. By including these effects an improved deflection theory is proposed. It is made clear that Timoshenko's theory has two problems : indistinct definition of deflection and wrong inclusion of the other deformations than that caused by bending moment into the shear ones.

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A numerical procedure including the incremental strain-controlled strategy proposed by the authors is presented here for analyzing the equilibrium path of elastic-plastic frame. Some numerical examples demonstrate that this strategy is an effective means to generate consistent stiffness matrix. The programming code for the incremental strain-controlled strategy can be easily produced from those for the well-known load-controlled scheme and/or displacement-controlled scheme.The incremental strain-controlled strategy can be conducted independently of the setting of system coordinates which is important to generate consistent stiffness matrix by means of the displacement-controlled scheme.

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The investigation was made to estimate the consolidation yield stress of cohesive soils by using sounding tests. The allowable stress of a ground was considered in taking account of the allowable settlement. It was found that the ratio of the undrained shear strength to the effective vertical pressure for normally consolidated soils under K_0 consolidation can be determined approximately as a constant of 0.375 irrespective of plasticity index. The consolidation yield stress of overconsolidated soils subjected to K_0 consolidation was estimated from upper and lower bounds simulated by the proposed model. Similarly, the consolidation yield stress of incompletely consolidated soils was predicted. Furthermore, an analytical method to calculate the allowable stress was proposed for the multi-layered ground.

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In regard to the grounds of small buildings, discussions were made on various issues and the evaluation method of the Swedish weight sounding test. Main conclusions obtained are summarized as follows. 1) If the maximum diameter of screw point has been worn down by 3mm, the Nsw value becomes larger in hard ground. 2) In hard ground, Nsw value obtained using an electric type testing machine becomes larger in comparison with that obtained using a manual type testing machine. 3) It is sufficiently possible to evaluate the friction force of rod circumferential surface by drawing it out.

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Various reports on damage to pile foundation of buildings due to 1995 Hyogoken-Nambu earthquake indicate the need to develop techniques for quick and accurate assessment of damage to piles following major earthquakes. In this paper, the monitoring sensor using the carbon fiber enclosed between glass fiber reinforced plastics is proposed. First, the performance requirements in monitoring the integrity of piles are discussed, and the applicability using the carbon fiber is confirmed comparing with other sensors. The proposed sensor has many advantages, for examples, a small section, a long-length, a good durability, an easy inspection using an electric resistance tester, etc. And also, the mechanical properties both of a carbon fiber and the sensor are investigated through the several type tension tests. As the result, the proposed sensor has the applicability in monitoring the integrity of structural elements, in which the discrimination is determined as the elongation percentage of the fiber, and the maximum strain is memorized referring to the residual electric resistance.

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In this paper, 38 four-pile caps were tested, and the relation between the ultimate strength of four-pile caps and the distance from the periphery of the pile cap to the center of the pile was examined. As the result, it became clear that the ultimate strength of pile caps having thick slab and uniform bar arrangement decrease as the distance becomes shorter. And it became clear that pile caps having short the distance failed in shear before bending yield or after that, even if the calculation predicts flexural failure. The required the distance that the ultimate strength of pile caps having uniform bar arrangement does not lower in comparison with the calculate values seems to be about 1/2 of the pile pitch.

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The short-term flexural behavior of reinforced concrete composite beams composed of precast units that developed cracks due to construction loading was investigated in the authors' previous paper, in which a stress analysis method for such composite members was proposed. As part of a study series, this paper reports on the long-term behavior of such beams. Three parameters were considered in the sustained loading experiments : the level of construction loading on precast units, depth of precast units and the existence of prestress on precast units. As a result of sustained loading for up to 3 years, the long-term increments of crack width and deflection of such composite beams with cracked precast units were smaller than those of beams which were not loaded at the construction stage. The composite members were proven serviceable and useful. The results calculated by the proposed analytical method agreed with the measured values.

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Horizontally haunched beams are being increasingly used to prevent brittle fractures of beam flanges in the vicinity of steel beam-to-boxed-column moment-resisting connections. The design method has already been proposed by the author and used in practical design. This method can give fracture patterns and the optimum haunch length by comparing fracture strengths and local buckling strengths of the beam-end. However, the formula of local buckling strength used in the design method has recently been corrected, and a formula for strength against diagonal fracture based on von Mises's yield criterion has been proposed. This new knowledge needs to be included and verified to refine the design method. The revised design method has been applied to horizontally haunched beams tested by the author and other reseachers. The followings have thus been clarified. The formula for the diagonal fracture strength provides some conservertive result on the safe side, and the corrected local buckling strength agrees closely with the test results. Furthermore, the refined design method is reconfirmed to indicate roughly fracture patterns and optimum haunch length, except for beams with stiffeners. An equation for optimum haunch length is also proposed. The rough value of the optimum haunch length is about 20〜30% of the beam depth.

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To develop a rational stability design method for a rigid multi-bay multi-story frame with slender columns, an interaction between buckling of the slender column and frame instability is studied. First, a characteristic equation for a single buckling of the slender column elastically restrained by other members is derived for simplified models. Through an analytical and numerical study carried out, the condition that the slender column buckles prior to the frame instability is investigated. Then, a simple method to evaluate the above condition is proposed for a practical design purpose. Applicability of the proposed method is also demonstrated and discussed.

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This paper proposes a method to predict the maximum seismic response of the single-degree-of-freedom systems whose load-dis-placement relationships are represented by polylinear models. Based on the balance between earthquake input energy and absorbed energy during a half-cycle of vibration, the maximum seismic response is derived as functions of damage-causing earthquake input energy and the maximum half-cycle energy input ratio. The applicability of the proposed method is confirmed through comparisons with numerical results of various single-degree-of-freedom systems.

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Theoretical studies are presented on the elasto-plastic behavior of a composite beam-column, subjected to non-symmetric bending. An approximate method is introduced for elasto-plastic analysis by assuming the column deflection curve as a part of a cosine wave. Computed results show good agreements with experimental and detailed numerical results. A stationary condition is also introduced for the maximum strength in explicit manner. The maximum strength of a beam-column subjected to non-symmetric bending is directly obtained without any step-by-step calculation. Computed results show good agreements with numerical results.

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This paper describes the mathematical characteristics of a layered arch with fractal geometric form and its application to structure and architectural design. Fractal dimension of the structure is acquired from geometric formulae derived here and its value ranges from 1.0 to 1.24. Subsequently structural data for frame analysis are generated automatically using IFS(Iterated Function System) code. Analytical results show the stress distribution of the main beam of the layered arch is similar to a normal arch as a whole. The displacement of the arch at the roller supporting point is 5.68% larger than one of the normal arch to vertical loads when parameters related to the configuration θ and ε are 23° and 0.02. However the former become less than the later with increase of the rise angle. Finally the complex architectural space with self-similarity and non-integer dimension is visualized through a 3D design example.

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