The yield value of unsaturated polyester resin mortar is not clearly observed and the viscosity of resin varies depending upon the change of temperature and the mix proportions of diluent. Therefore, it is difficult to decide the mix proportions of the resin mortar according to the same design procedure as that of cement mortar.
In order to make clear the relation between the mix proportions of resin mortar and its workability, viscosity, flow, and segregation tests were carried out. From these test results, the workability of the resin mortar was found to be estimated by the viscosity of resin and resin paste.
Based on the results, the mix design of the resin mortar with a constant viscosity is proposed in this paper.

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The design and construction manual of concrete pavement in Japan introduces standard thicknesses of concrete slab ranging from 15 to 30cm, that are based on the analytical design method proposed by P. W. R. I. almost 20 years ago. The analytical design method is to determine a slab thickness based on the fatigue, which is computed by the magnitude as well as the number of the repetition of the resultant stress of wheel load stress and thermal stress.
This paper reports the performance survey of experimental concrete pavement sections of Yaita Bypass, which was constructed in 1968.
Useful findings of the survey are 1) the effectiveness of the use of asphaltic mixture on the top of base course, 2) the proposal of the use of strong dowel bars, 3) the possibility of transverse joint edge approaching the critical instead of longitudinal edge etc.

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Finely-divided copper slag made by granulating slag produced in refining of copper will improve the filling properties and uniformity of grout and is thought to be usable as a grout admixture, but there is substantial reduction in the strength of grout. The study reported here was for the purpose of developing a grout for prepacked concrete having filling properties and uniformity that are good as well as ample strength through the combined use of a grout material containing a high-range water-reducing admixture with finely-divided copper slag. Uniformity was ascertained by mix proportion analyses of various parts of 180×60×15-cm prepacked concrete specimens and core strengths, while analyses of liquid level gradient of the grout were also performed to show the advantages of copper slag grout.

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We investigate the utilization of steel slag for road construction materials, mainly for asphalt mixtures. This report consists of two parts. Part one; the general character of steel slag aggregate and asphalt mixture with steel slag that have completed 3-6 month aging. Part two; the character of asphalt mixture respect to the aging. According to the result of this study, We can conclude that the material that have completed over 3 months aging has stable character for pavement of anti-plastic flow and anti-abrasion.

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Tension stiffening in a reinforced concrete member has been known to result from crack formation and bond-slip between the reinforcing bars and the surrounding concrete. The authors develop an analytical model for the stiffness of reinforced concrete uniaxial members with gradually forming cracks based on the bond-slip mechanism. Crack strain, defined by the derivative of the local slip, is introduced as inelastic strain and contributes to making resonable formulation for the analysis of a cracked concrete field. In the paper, purely theoletical solutions of stress-total strain relations of cracked reinforced concrete are presented for both linear elastic and elastic brittle fracture models of local bond-slip relations. Finally, the authors' model is proposed and compared with experimental results from other researchers.

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A total of eight ferro-nickel slags were studied for their possibility of being used as fine aggregate in concrete. Special emphases were placed on their effects on the freeze-thaw resistance and long-term stability of concrete. It was observed that the freeze-thaw resistance of slag concrete was generally lower than that of ordinary concrete with river sand. The increased bleeding of slag concrete was mainly responsible for the low freeze-thaw resistance. Slags which were composed of only forsterite and amorphous silica were found to cause a reaction with alkalis in concrete, while other moderately-cooled slags were stable. Grain popouts were observed when certain slags were used. Three slags were considered not to impair the durability of concrete. Properties of fresh concrete were also discussed briefly.

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It has been recognized that the behaviors of R/C members under dynamic loading are different from those under static loading due to strain rate effects of materials. This paper describes the effects of strain rate of reinforcing bars on the dynamic response of R/C structures subjected to earthquakes. In order to obtain accurately the dynamic response of R/C members subjected to earthquake motions, the new force-displacement model was proposed based on the effects of strain rate of reinforcing bars. The dynamic responses, especially accelerations, calculated using the proposed force-displacement model resulted in satisfactory agreement with the measured responses. Furthermore, the influences of strain rate on R/C structures subjected to actual earthquakes were clarified using the proposed force-displacement model.

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Temperature distributions in asphalt pavement with depth and time were measured every hour for a year continuously. As a result of statistical analysis, it was found that the difference of pavement structure does not affect surface temperature significantly, and that pavement temperature is related not only to changes in air temperature but also to other climate parameters, including changes in solar radiation, wind velocity and precipitation.
Temperature distribution in pavement was also estimated theoretically by a heat flow model proposed in which the heat transfer coefficient at the pavement surface and thermal diffusivity of the pavement materials were taken into account.

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This study had the purpose of experimentally investigating the influence of cutting off reinforcing steel bars in tension zones on the failure modes and shear strengths of reinforced concrete beams. The main variables were tensile reinforcement ratio, shear-span ratio, stirrup ratio, and cutoff location, and loading was static one-way monotonic loading. As a result, it was learned that the failure modes of such beams can be divided into four classes mainly according to cutoff location and stirrup ratio, and that shear strength depends on these factors also. Further, one side cyclic loading was done on two specimens and reductions were seen in shear strength of beam without stirrups and in deformability after yielding of beam with stirrups.

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A new fatigue failure criterion of asphalt mixes which is applicable even at low stiffness modulus under high temperature or low loading speed is proposed. It is found that the dissipated energy per cycle per unit volume in asphalt mix at the instant of fatigue failure can be a rational failure criterion. Then the fatigue failure envelope based on experimental results at high and medium stiffness modulus is adjusted at the low stiffness region. And also it is found that the fatigue damages of asphalt pavement can be neglected under high temperature or low vehicle speed. The validity of the new criterion is verified by comparing with other proposed failure criteria and some field data obtained by public road administrators.

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This study has made a multiple regression analysis using data resuils of various concrete testings and data from the construction sites of the expressways.
Then we have clarified the relationship between compressive strength (Y) and condition of material, mix proportion, etc. (X₁, X₂, …, X_n).
Furtheremore, we propose the concrete quality control system by which the compressive strength of concrete can be calculate by use of the multiple regression expression instead of strength tests as follows; Y=A+B₁X₁+B₂X₂+…+B_nX_n
where, A, B₁, B₂, …B_n: constant

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In order to produce the prepacked concrete of high quality, it is important to fill up the voids of preplaced coarse aggregate with mortar perfectly.
The author had proposed a theoretical method for predicting the process that the voids of the coarse aggregate were grouted.
As an example of practical application of the theory, relationships between the maximum gradient of mortar surface and performance conditions were calculated, and further, a procedure to decide the adequate grouting conditions was offered.

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