Under bending, shearing and bonding stress, the reinforced concrete members containing sintered fly-ash coarse aggregate show a tendency as follows, the space and width of cracks are slightly narrow, the stress at the first crack occuring is higher about 20 percent, the stress at ultimate and the capacity of deformation are slightly advantages over that of expanded shale type members.

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Based on the detailed investigasion on corrosion characteristics of light gage steels which are structural member of housing, classificastion by visual observation of external form of rust is suggested newly. External forms were possible to classified into 6 types i. E. froth like corrosion, oil film like corrosion, spite-hole like corrosion, film peeling like corrosion, chip-off peeling like corrosion, and layerd peeling like corrosion. Factors of corrosion for respective kind are possible to estimate through molecular constitutional ratio of rust which was obtained by X-ray diffraction analyses, and constitutional ratio of element of rust which were obtained by EDX analyses. In addition, reduction of thickness of steel by corrosion and extreme value of corrosion depth were found to enable the estimation of corrosion rate respectively. In the second place, data of dismantling investigation of 32 houses were analyzed statistically by 2 evaluation methods, namely degradation degree and classification of external form which are included in diagnostics for rusts on painted steels. As the results of analyses, common factors were ascertained and classification by external forms was found effective.

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We study the historical changes and backgrounds of the numerical formulas appeared in the regulations for structural calculation. The regulations and their drafts, from the Drafts of Tokyo City Building Ordinance planned by members of A. I. J. to the Urban Building Law Enforcement Regulations, are surveyed in this study. The majority of formulas had been deleted once in the Drafts of Tokyo City Building Ordinance. But later all of them restored to the Drafts of Tokyo Prefecture Building Regulations planned in the Metropolitan Police Department, or to the Urban Building Law Enforcement Regulations. The Urban Building Law Enforcement Regulations had new formulas which had been prescribed in the Drafts of Tokyo Prefecture Building Regulations. The formula regulations started to be independent from copy of foreign regulations.

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In this paper, the analytical method to estimate for ultimate shear strength of reinforced concrete members with biaxial sections, circular and diamond section, is proposed by authors, and is based on a plastic analysis. 2) On the analytical method, the divided rectangular sections have been cuted out between the longitudinal bar in biaxial section, and the amount of the reinforced bar has been distributed in order of the divided rectangular sections having large area. The shear strength of the divided rectangular section has been calculated by the extend addition strength theorem, and the ultimate shear strength of R/C members with biaxial sections has been calculated to add up to each of the shear strength of the divided rectangular sections. The parabolic distribution of shear stress occurred in circular section is estimated by the analytical method, and it is evident that this distribution of shear stress in circular column transforms according to the amount of reinforced bar and longitudinal reinforcement. This analytical method can not be adopted for design method because of complicated calculation. The design method must be simplified, and we have often used to the approximate method which shear stress occurred in circular section is constantly distributed, conventionally. Therefor, the reliability of both the analytical method and the approximate method is examined. It is evident that the solutions calculated by both the analytical method and the approximate method correspond well with the experimental results, respectively, and that the approximate method is more effective on design method.

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The seismic properties of reinforced concrete members have been increasing elucidated while the shear transfer mechanism has not yet been grasped. The shear failure of reinforced concrete members is a complex phenomenon influenced by a diversity of factors, and this is one of the reasons that a number of experiments carried out to date were unable to fully grasp the phenomenon of the shear failure of the reinforced concrete members. As it is impossible to assess all phenomena of shear failure only by experiments, the results of an experiment must be recorded accurately and carefully to create an adequate model for analyses. This paper discusses in detail the results of experiments on reinforced concrete members subjected to shear force which monotonously increases under a constant axial load. The shear reinforcement ratio and the degree of compressive axial force are used as parameters. The paper concludes as described in the subsequent paragraphs. 1) With a diagonal shear crack occurring in a reinforced concrete member, the concrete element is almost unable to transfer the shear force, which shear reinforcement is able to. 2) The magnitude of shear force transferred by the shear reinforcement is affected by that of the axial force, and the ultimate shear strength is largely affected by the axial force. 3) Photographing facilitates the measurement of two-dimensional deformation as well as that of the deformation in the vicinity of a crack which cannot be predicted before experiment.

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A design procedure is presented to prevent the shear failure of reinforced concrete members after flexural yielding. The procedure is based on truss-strut model. The inclination of truss action is assumed to increase in hinging regions considering reduced aggregate interlocking. Effective compressive strength of concrete is assumed to degrade in hinging regions considering crossed shear cracks. The procedure is confirmed by existing experimental data.

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The method of analysis for long-term bendings have not been fully established in reinforced slabs under service loads. Even on instantaneous bendings, several problems for analysis on it have been remained unsolved partly though some methods for analysis which have effective work within relatively small deflection, several millimeters, have been proposed. The first reason of such a situation is that analytic treatments for slippage of tension steel at slab's edges is uncertain. The final purpose of this studies is to estabilish a method of analysis on long-term bendings in reinforced concrete slabs, and as a part of studies and the first part, analytic treatments for slip-page of tension steel is proposed, and an analytic method for instantaneous bendings considered slippage in one way slabs is shown. The validity for this analytic method is investigated with previously published test data. Furthermore, by utilized those analysed results, several examinations are carried out. The followed results is obtained. (1)γ〜s relation of bi-linear type proposed in this paper can be applied satisfactorily for the calculation of slippage of tension steel. (2) The analytic method in consideration of slippage of tension steel in this pater suitably estimates instantaneous deflections and re-arrangement of stresses after being cracked. (3) At least, the creation for allowable unit stress of tension steel for service loads has no effect for control of deflections or cracks on instantanous bendings of reinforced concrete slabs.

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Due to the lack of deformability of R/C short columns, it is very important to treat strength and deformation simultineously in analytical study. In this paper, Direct Compression Field and Indirect Compression Field (Truss) are used to simulate the shear resistant mechanism of R/C short columns. Firstly, a lower bound analysis is performed, and the variation of shear resistant mechanism as well as the stress conditions of the columns are discussed. Then, a macro-model is developed by Equivalent Axial Strength methods, and comparison is carried out with the lower bound analysis. By taking account of flexure resistance properly into the above macro-model, a macro analytical model is constructed for R/C columns subjected to combined bending, shear and compression force. Using the above macro-model, strength surfaces of R/C columns are obtained, and through deformation analysis, the elastoplastic deformation behaviors and failure modes of R/C columns are clarified.

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Steel wide flats (SM50A) produced by electric furnaces are gradually used as plate elements of the main members in steel building structures, as well as ones by blast furnaces. In Japan, 6 makers produce this kind of flats, which range of the sectional sizes is from 19mm×200mm to 36mm×300mm. These are inclined to include so-called "tramp elements", for example, Cu, Cr, Sn, so on, because the main raw material is supplied from scrap iron. Therefore, it is necessary to clarify the fracture behavior and mechanical characteristics on the base metals and the weld zones, when these are adopted to the flange plate of columns, especially at the portion of the beam-column connections, where the stress state is very complicated. The present report describes the controlled temperatures at tapping teeming, preheating and finishing of rolling. It also summarises the chemical components, grain size and non-metallic inclusions. Tension tests and V notch Gharpy tests are carried out to clarify the anisotropy of mechanical properties and impact toughness of base metals. Maximum hardness is measured along a line at the section of the weld zone. The impact toughness at the welded joints are investigated by use of the V notch Charpy specimens sampled from the weld interfaces and heat affected zones. Finally tension tests are executed by cruciform welded joints. The all test results obtained from the steel by electric furnaces, are compared with those from the steel by blast furnaces.

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The composite unbonded bracing is a member that consists of a core steel bracing (made of a built-up square hollow section) which is encased firstly by an unbending material in order to re-duce bond-stresses, and after by reinforced concrete. The main role of the use of reinforced concrete is to prevent an overall buckling in the core steel bracing. The role of the unbending material is to make independent both the core steel bracing and the RC part when axial loads are applied, due to that RC can not work for this type of loading. For tension and compression loading conditions, their corresponding stiffness and strength are in-tended to be same. Experiments on 16 specimens were performed to make clear the effects of the following parameters under cyclic axial loading; For the core steel 1. Slenderness ratio Bracings with medium range slenderness ratio (40-80) were mainly studied in these ex-periments. 2. Width to thickness ratio of the square hollow section. For the encased reiforced concrete 1. Quantity of axial reinforcing bars 2. Quantity of hoops 3. Strength of concrete 4. Thickness of concrete cover From these experiments, it can be confirmed that a properly designed composite unbonded bracing has a large ductility in an elasto-plastic range under axial cyclic loading.

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Theoretical and numerical study on determining the load and strength factors in probability-based limit state design is presented. The method and procedure reported in the preceding paper11 are applied to calculate the load and strength factors in combinations of dead, live, snow, wind and earthquake loads and sensitivity of the load factors to the load parameters, i. E. intensity, occurrence rate and duration of each load, is investigated in this paper. Sensitivity analysis shows that the load factors on snow and wind loads are sensitive to the c. o. v. 's of their intensity and that the load factor on earthquake load is sensitive, to the c. o. v. of the intensity and to the occurrence rate of earthquakes.

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