Although many reinforced concrete rock shelters have been designed against static loads that are of same level as the maximum rock impact, the design should be carried out by dynamic analyses.
In order to grasp shelter slab's behavior under falling rock impact, we executed dyna-mic and static loading experiments on RC slabs with sand cushion. It was found from the results that impact force brings far less displacement or strain to RC slab than that of static loading case. Time-lag between impact force and slab's response explanes most part of such difference. The result of these experiments were ascertained by F. E. M analyses, and at the same time, a dynamic design method for rock shelter was presented.

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A test pavement with a chemically stabilized layer was constructed and periodically investigated by a non-destructive method. Three years after the construction of the pavement, a large portion was dismantled to allow deflection measurements on the surface of each underlying pavement layers (base course and subbase course). Field CBR tests were performed over the stabilized layer and samples were also extracted of laboratory CBR and other tests.
This paper describes the results of the structural evaluation of the test pavement using the modified Benkelman beam, and the comparison of the laboratory CBR and modulus of evaluation (or modulus of deformation) of stabilized layer.

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Quality control tests of concrete are usually made by testing compressive strength of hardened concrete at an age of 28 days with specimens taken at the unloading point. But it is important to get a decision on concrete quality at an earliest age possible, and the results be utilized in further concrete production and construction works. From this point of view “the Quality Control Systems of Concrete by Data Analysis” is suggested. In this system the estimating method of concrete quality is utilized as follows: The compressive strength and other qualities of concrete can be calculated by estimation equations using such control data as the test value of materials to be used, the printed record value of baching, the property of fresh concrete, etc.. In the case of the mix design and production control this method can be used efficiently without testing hardened concrete.

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The failure mechanism and the punching strength of RC slabs damaged by corrosion of reinforcement are not only experimentally but also theoretically studied in order to obtain useful information for repair or maintenance. In the experiments, loading tests are conducted for RC slabs damaged with an accelerated galvanostatic corrosion method. It is found that the reduction in punching strength and the change of failure mechanism occurred in the damaged slabs. The modeling of failure mechanism of the damaged slabs is investigated by experimental and theoretical consideration using elastoplastic finite element analysis. From these consideration, it could be indicated that the punching strength of the damaged slabs is composed of the ultimate shear strength in compression zone under the loaded area and the bending strength of the main reinforcement with the bottom covers.

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The acoustic emission behaviors of repaired reinforced concrete beams under flexure load was studied. Useful correlation was established between the acoustic emission activity and crack growth in the repaired reinforced concrete beams. Three different acoustic emission activities were observed during the flexural loading. Flexural crack initiation, flexural crack propagation and slip between repair material and old concrete were identified by monitoring the acoustic emission. The zone of slip initiation and development can be identified from the acoustic emission event-location plot, showing major acoustic emission concentration areas. Repetitive loading showed that the Kaiser effect was not valid after slip was happened at the connected face between repair material and old concrete. Flexural crack growth acoustic emission burst event signals were found to be of higher amplitude compared with those due to the slip. The accumulated number of burst events of these highamplitude emissions, monitored by the use of a high threshold, showed good correlation with the crack growth in the beam.

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This paper deals with the effect of rock as aggregates containing montmorillonite on the volume change, compressive strength and Young's modulus of the concrete. Ten types of coarse aggregates were used in this study, which were andesite, basalt, sandstone and slate rock. The contents of montmorillonite in aggregates were determined with a microscope and by X-ray analysis. The concrete specimens were cured in (1) standard manner (2) wet and dry condition cycles (3) high temperature at 60°C, 110°C and 200°C and (4) freezing and thawing cycles.
The summary and conclusion are follows
(1) The higher the content of montmorillonite in aggregates of sedimentary rocks, the higher volume change of the concrete specimens was observed.
(2) When the content of montmorillonite in sandstone aggregates exceeds 5%, the aggregates influence on the properties of concrete.

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This paper discloses that a fairly substantial part of the reduction in compressive strength of concrete in which alkali-silica reaction has occurred is not due to the alkali-silica reaction itself, but because of such facts that alkali in cement makes the structure of the hardened cement mass porous, that there is a great difference in the tendencies of compressive strength reduction between cases of using glassy andesite and chert as reactive aggregates, and that the ratio of decline in compressive strentth becomes very low when expansion due to alkali-silica reaction reaches about 0.2%. Furthermore, it is shown that along with non-crystalline part in the constitution of concrete being increased with progress of reaction, there is an increase in homogeneity of structure, backing up the results obtained through experiments.

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In order to evaluate the performance of asphalt pavement with a slag base, truck tests were conducted on a 12m radii circular test road consisting of various pavement sections. The new slag base material tested was a compound slag (mixture of 50% by weight of steel-making slag, 30% of blast-furnace slag, and 20% of granulated slag), and the reference materials utilized were a blast-furnace slag, crushed stone, and asphalt concrete. Through five series of truck tests, the data of performance such as deflection, cracking, and rutting were periodically collected and compared to evaluate relative performance. Moreover, for the purpose of generalizing the performance data observed, three theoretical procedures regarding structure analysis, fatigue prediction, and rutting prediction were proposed and examined through the observation data. This paper describes the performance data observed and discusses the applicability of the analytical methods proposed.

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The purpose of this study is theoretically to clarify the ultimate shear strengths and the deformations of reinforced concrete beams with web reinforcement, subjected to combined bending moment and shear. To achieve it, ultimate equilibrium method based on the energy principle is applied. The proposed equations which are derived by equilibrium condition of force and moment for the failure surface on the ultimate state are compared with test results and good agreement is noted. And, compatibility condition of strains on the shear element is considered to predict the failure mode of beams. Also, the interaction between bending moment and shear is proposed.

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In order to generate non-uniform self stress that is defferent in area of working zone, partial surface provided by controlling coating area of mortar beams was exposed to drying condition at first. Distribution of self stress thus generated was experimentally determined by measuring variation in strain when a part of a specimen was cut or notched. Next, beams were loaded flexurally and failure condition was examined. It was proved that the maximum tensile stress obtained by superposing stress due to external load upon the self stress did not serve as a failure criterion.

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This paper discribes the method that places set-retarded concrete between alreadeyplaced concrete and newly-placed one in order to reduce thermal stress in the vicinity of construction joints of massive concrete. The purpose of this study is to prove the effect of the method. The experimental study is performed with two actual size 20m long specimens, a conventional concreting method and this new one. It is found to be particulaly effective in reducing temperature gradient of newly-placed concrete, decreasing the ratio of restriction and reducing thermal stress and to be able to prevent thoroughly occurrance of cracks in newly-placed concrete by use of this new method.

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The analytical method of elasticity about paving materials on the pavements has many features. (1) Analytical data are used the impact waves on human body. (2) The impact force on legs is valued the total impact acceleration velocities of knee and amkle. (3) The frequency of impact wave has the correlation to results of function test about elasticity on a pavement. (4) The deformation of materials is shouwn the integral value.

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The purposes of this study are to clarify the effect of the static flexural strength of concrete on the fatigue strength equation and to determine the design fatigue strength equation to take the reliability of concrete pavement into accout. As a result of the statistical analysis of the fatigue tests, it was found that there is almost no effect of the static strength on the fatigue strength equation for concrete pavement design. By means of the present simulation which took account of the scatters of the fatigue strength, the relationship between the failure probability of the flexural fatigue strength equation and the reliability of concrete pavement was obtained.

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The object of this paper is to investigate experimentally the influence of tension force and cover on the dowel effect of axial bars. Failure mode, dowel force-displacement relationship, dowel capacity and deformation of bars were investigated in detail under dowel load and tension force simultaneously. As a result, we found that dowel capacity increases as the thickness of cover increases, but its capacity decreases exponentially with increasing tension force. Furthermore, it is pointed out that the dowel effect of axial bar depends on the characteristics of concrete rather than those of bar. Finally, the posibilities of introducing the dowel effect into shear strength of RC members in design were discussed.

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This study was made to present a method for nonlinear coupling analysis of heat conduction and temperature-dependent hydration of cement and to indicate the difference of analytical results between the conventional linear method by using an adiabatic temperature rise curve and the proposed nonlinear method by using the temperature dependent heat hydration model. For the cement hydration model, the heat generation rate depending on the temperature and past hydration process was adopted as a function of temperature and accumulated heat.
This nonlinear analysis results are considerably different from that of the conventional linear analysis in case of thin wall type structure. The proposed nonlinear analysis is able to express the actual behavior occurred in the concrete structure with high fidelity.

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Transient performance of the cracking damage of concrete pavement slab was modelled by means of the statistical analysis of the results of the condition survey of pavement surfaces. In the modelling, a double exponential function was applied to the formation of the cumulative distribution function of the annual increment of the cracking index. The validity of the model was verified statistically by the goodness-of-fit test between the surveyed cumulative frequency and the calculated distribution by the model. Reliability of concrete pavement against the cracking damage can be evaluated by this model.

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The phenomenon of water being sucked up is focused on with the objective of establishing a testing method for capillary infiltration in concrete. Capillary flow inside concrete is first analytically studied, and together with showing that the physical property values for evaluating watertightness of concrete are final infiltration height Z_e and capillary infiltration coefficient K_c, methods of obtaining these by simple means are presented.
The reliabilities of the capillary infiltration property and test values are discussed comparing with the cases of other permeability test methods to indicate that the capillary infiltration test can be a useful method of conveniently testing watertightness of concrete.

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The purpose of this study is theoretically to clarify the interaction among ultimate strengths of reinforced concrete members with web reinforcement, subjected to flexureshear and axial load simultaneously. Ultimate equilibrium method which is based on the energy principle is applied in order to evaluate the shear strength of RC member. The proposed equations are derived by equilibrium condition of force and moment for the failure surface on the ultimate state. And compatibility condition of strains on the shear element is considered to predict the failure mode of member. The interaction curves among three ultimate strengths -bending, shear, and axial capacities- are theoretically proposed. Furthermore, this study involves some significant considerations for the design method.

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The establishment of test methods for determination of the tension softening diagrams of concrete has been desired. In this contribution, following the discussions on the existing J-integral approaches a simple and handy test method for determination of the tension softening diagrams from bending tests on notched beams is proposed. The method has the following features: (1) the tension softening diagrams can be determined from a single beam specimen, (2) the method can be combined with the RILEM method for determination of the fracture energy G_F, (3) only the load, the loading point displacement and the crack opening at the notch tip are necessary to be measured, (4) the second derivative of the potential energy is introduced to improve the accuracy of the estimation of the diagrams. The proposed method is applied to concretes including high strength concrete and light weight concrete to determine tension softening diagrams, and the validity of the method is certified.

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The function of shock absorbed about artifical sand grass were examined to elasticity by the method of analysis to impact wave on human body about the 18 different species of pavement. It is concluded. The thick surface course material show the more effective function of shock absorbed. But surface course material is more effective than layer course materials, and there is not effect of bedrock materials. Good function of shock absorbed like the truf are granular rubber with polypropylene net and blister urethane mat.

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The objective of this research is to establish the deformational compatibility for aggregate phase of concrete in bend pipes used for concrete pumping. The deformational compatibility, which describes the relationship between the strain rate of aggregate phase (particle assembly) developing over a reference section and sectional mean flow speed of the particle assembly, is essential in one-dimensional computation of dense liquid-solid flow in pipe lines. Flow visualization and image processing on model concrete were carried out for development of the mathematical description of the deformational compatibility for aggregate phase in bend pipes, in which the second strain invariant of aggregate phase was adopted as a main parameter associated with stress generation due to particle-to-particle interactions. The authors have proposed a simplified compatibility formulation reduced to one-dimensional condition and applicable to dense liquid-solid flow in bend pipe portions, by relating the sectional averaged invariant of strains to the mean flow speed of solid phase and the curvature of bend pipes.

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The present paper deals with investigations conducted on deformation of asphalt mixture in road pavements. Since loads are constantly applied to pavements in a certain direction by passing cars, the wheel tracking tester was modified so that the wheel loads were applied in one direction only. It has been pointed out that deformations are more likely to occur under loads applied in a single direction. Burial of steel strips joined together in a grid in the asphalt mixture was proposed as a method of reducing the deformation. The test results indicate that the burial of steel grids is a most effective way of reducing the deformation.

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This paper deals with permeation limit of suspension grouts with ultra-fine granular materials, which have high strength and high durability as compared with solution grouts. Through a lot of injection tests, effects of grain size of granular meterials and concentration of suspension on permeation limit are investigated. Main conclusions are summarized as follows: 1) If the specific surface of granular materials is smaller than 10000cm²/g (Blame method), the groutability G_RC is 15-25, irrespective of grain size and concentration. 2) The permeation of grouts does not always improve as the grain size becomes smaller. In the relation between the finess of granular material and the groutability, the practicable maximun finess is 5μm in G₈₅ (=grain size of 85% as percentage finer by weight) and 10000cm²/g in specific surface.

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