A new method for analyzing the behavior of fresh concrete, i.e., a viscoplastic divided space element method (VDEM) is proposed, which is applicable to simulate the flow and deformation of fresh concrete in practical concreting works, and some analytical results are shown in this paper. This method can be applied to calculate the large deformation of fresh concrete at casting in the form in which reinforcing bar and steel exist, and also to examine the effect of vibration. Such characteristics and applicability of VDEM are compared with the viscoplastic finite element method (VFEM) and the viscoplastic suspension element method (VSEM) proposed earlier by the authors.

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An experimental study on low-heat type blended cement containing ground granulated blast furnace slag is reported in the paper. The influences of factors such as mixing ratio and specific surface of blast furnace slag and the mixing ratio of gypsum (S0_3) on heat evolution and strength development characteristics of cement and concrete were ascertained, and a cement of a composition providing favorable strength development while generating lower heat was proposed. Thus, a blast furnace slag cement of low-heat type has been attained. This blended cement is suitable as a cement for controling thermal cracking of mass'concrete structures requiring comparatively high strength.

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This report made a test study about effects of quality and kinds of coarse aggregate and 400kN crushing value and maximum size on compressive strength and crushing condition and compressive deformation of ultra high-strength concrete (about 90-130 MPa) The results are shown as follows, (a) When 400kN crushing value of aggregate is 11-23% and water-to-cementitious ratio is less than 0 25, this strength is concluded for material and mixing proportions of ultra high-strength concrete (b) Compressive strength of concrete increase with decrease in maximum size of coarse aggregate Compressive strength of concrete made with limestone and hard sandstone (A) graded at 10-5 mm is about 106 MPa and about 117 MPa, which is 2-6% higher than that of concrete made with a grading of 20-5mm (c) Compressive strain increase with decrease in grading of coarse aggregate When compressive strength of rock reduces, we can't find any difference in grading (d) In order to get compressive strength of ultra high-strength concrete, it is necessary to raise compressive strength of rock and crushing strength and grading (maximum size) of coarse aggregate and bonding between coarse aggregate and mortar and at the same time to bring strength and deformation of aggregate close to strength of aggregate and deformation of matrix mortar or increase it

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In this paper experimental investigations were conducted considering the interaction of fiber length fiber volume fraction and matrix strength on the fracture toughness of steel fiber reinforced concrete (SFRC) The method is based on the evaluation of tension softening in the fracture process zone by means of a reverse analysis of the cohesive force model As the result the following aspects were derived Both of the fiber-bridging stress and the fracture toughness in terms of the J-mtegral value of the SFRC increase as the increase in cement-water ratio (C/W) of the matrix and the extent becomes markable with'the longer fiber The interaction of fiber aspect ratio (l_f/d), fiber volume fraction (V_f) and C/W on the, fracture toughness of the SFRC can be expressed by the parameter of (l_f/d)√<V_f>√_<C/W> in the high correlation with the fracture toughness

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The dynamic shrinkage-water loss curves for thin cement paste specimens (4×0.4×15cm) with 0 35, 0 45, 0 55 and 0 65 W/C ratio at the age of 3, 7, 28, 77 and 186 days, respectively were investigated under the drying condition of nearly 0 % rh It was found that the S-W curves were constructed of three phases The shape of the curves at an early stage of drying was considerably affected by the water cement ratio and the age at the start of drying These phenomena were able to be expressed unitanly by the ratio of, the amount of free water to the amount of evaporable water in a specimen The shape of the curves in the later half of drying with no free water in a specimen was hardly affected by the water cement ratio and the age at the start of drying It was found that the drying shrinkage strain at each stage of drying was proportional to the combined water rate

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This paper presented evaluation indices and an evaluation method of horizontal shake of floors from a viewpoint of comfort, in the case a person feels horizontal shake generated by his action. First, based upon the relationship between Dmax (maximum displacement generated by human action) and human responses to horizontal shake, evaluation indices were presented. Next, we developed an apparatus for applying the approximate force to floors that was caused by human walking, and presented the method of applying force and the relationship between (DmaxJ (maximum displacement generated by the apparatus) and human responses to horizontal shake as an evaluation method.

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This paper presents evaluation indices and an evaluation method of horizontal shake of floors from a viewpoint of comfort, in the case that a person who is standing or sitting on floors feels horizontal shake. First, we presented evaluation indices based upon the relationship between D_<max> (maximum displacement of floors) and human responces to horizontal shake. Next, we developed an apparatus for appplying force to floors, and as an evaluation method we presented the method of applying force and the relationship between [D_<max>] (maximum displace- ment of floors generated by the apparatus) and human responces to horizontal shake.

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The paper presents the data analysis of a gust response of the surface pressure field around a simple model which consists of the low cylindrical wall and the shallow cone roof The wind and pressure data in the distance variable changed from the time variable by using the wind speed data make clear the correspondence to the length scale of the model. The intermediate linear system between the dynamic pressure as input and the surface pressure as output defines the shape of kernel in integration, instead of the pressure coefficient in stationary condition.

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Dynamic partial uplift analyses of a structure on a 3-D layered half-space are performed based on the substructure method in the time domain The ARMA type recursive evaluations taking account of the causality of dynamic stiffness are used to enhance computational efficiency for calculation of interaction forces The dynamic response of a rigid foundation for harmonic excitations is first performed Then, the earthquake response characteristics of a nuclear reactor building taking account of the partial uplift are described for both linear and nonlinear cases of the building The effects of the partial uplift on the responses are discussed

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This paper discusses the characteristics of amplification in subsurface layers, based on records on earthquakes observed at three locations on filled ground in the Osaka Bay area, with different ground conditions. In analyzing and determining the amplification characteristics, earthquake scale and propagation route were taken into consideration, referring to earthquake motions in the base rock of mountains surrounding Osaka Plain, and those in the diluvial layer 60 m under the surface of the filled ground. It was found that the amplification characteristics of eathquake motions in the filled ground vary conspicuously according to the structure of subsurface layers, up to approx. 60 m under the surface. It is particularly noteworthy that the damping effect of the Hedoro layer, between relatively hard layers, is very strong.

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Three-dimensional dynamic characteristics of structure-wall foundation-soil systems are investigated by considering arrangement effects of wall foundations. A hybrid approach combined with a finite element method and a boundary element method is employed for numerical analyses in the frequency domain. It becomes clear that arrangements of wall foundations does not much affect the structural response while the stresses of wall foundations and the nonlinearity of the soil inside the wall foundations vary with the arrangements. In .addition, a lattice type wall foundation can reduce effectively the nonlinearity of the soil inside the wall foundations against incident waves coming from every direction.

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This paper presents an evaluating procedure of ultimate strength of reinforced concrete cylindrical shell roofs with vertically supported edge beams. Differential equations of the roof with orthtropic materials are analyzed by applying the Galerkin's method. And, it is shown that stress resultants of the roof are few affected by a variation of Young's modulus of the shell. This let us evaluate the stress resultants after occuring concrete cracking on the shell. Then, an procedure that evaluates ultimate strength of three typical failure mechanism of the reinforced concrete cylindrical shell roof is shown and is examined by comparing with experimental study.

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Lateral load tests using one-third models were conducted to elucidate the influence of floor The test results indicated that the effects of cross-wall and vertical load on the lateral stiffness of building were not cumulative and varied with directions of floor joists, configurations of cross-walls and amounts of vertical load combined The effect of vertical load was more pronounced than that of cross-wall when the floor joists were installed in parallel to the bearing-walls The behavior of cross-walls depended on the aspect of whole building in addition to installations of bearing-walls and floor joists

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The object of this paper is to make clear that the contribution of steel fiber to the shear resistance of steel fiber reinforced concrete elements should be evaluated to be a kind of reinforcement as steel reinforcement, or to be a kind of concrete containing steel fiber This paper consist of experimental study and analytic one Experiment is performed on 12 specimens which have content ratios of steel fiber, steel reinforcements and angles between predicting failure surface and loading direction as parameters under S-type loading system Limit analysis is used in analytic study by considering both Johansen's yield line' theory and modified Mohr-Coulomb's fracture criteria As the result of comparison and examination between the experimental values and analytic ones, it is concluded that the idea evaluating the steel fiber of steel fiber reinforced concrete elements to be a kind of reinforcement element is reasonable

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Natural smoke venting is considered to be as the most popular method of smoke control in atria. It is important for sound disigns of the smoke control systems for atria to have understanding on how the efficiency of the method is affected by height and area of an atrium, heat release rate of the fire and the conditions of the vents and air inlet. In this study, a simple steady state two layer model is developed for natural smoke control for atria to investigate the efficiency of the system. The experiments using a 2[m] × 2[m] × 5[m] (height) atrium model are conducted to validate the model, to investigate the smoke behavior under different conditions of smoke control and heat release rate, and to evaluate the efficiency of natural smoke control under some conditions of atria and design fires.

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