Research and investigations on the structual concrete members in torsion have been actively done in many countries, from necessity for the application of practial design and as a subject for study.
This paper summarizes the contribution of past workes and several problems concerned with torsional behavior (cracking moment, rigidity and strength), and it concludes with a summary of themes for future research.

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The Shiinamachi Apartment House is high-rise building of reinforced concrete structure, the first of this kind ever built in Japan. This building was not only designed by a new idea for structural system, but also used a lot of new techniques and working systems to be developed in execution.
This report treats with the execution of this building, such as reinforcement, form, and concrete works, with the emphasis on concrete works on the point of the method and results of their quality control and management.

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[in Japanese]

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It is known that large hoop tension is induced in the concrete linings of hydro power plant conduit tunnel due to the high inner water pressure.
To carry such hoop tension with no crack formation in the lining concrete, the prestress transfer in the hoop direction will generally be most effective.
However from the technical viewpoint, the application of the usual mechanical methods of prestressing by tendons has many problems or difficulties, especially in the case of tunnel linings.
The first attempt of chemically prestressing of the lining concrete had been made in Japan at the construction work of high pressure tunnel of Shimo-Kotori Hydro Power Plant by the Kansai Electric Power Co. Inc., and the works of chemically prestressing by the use of calcium sulfo-aluminous expansive cement concrete had been successfully done in the field.
This paper describes the laboratory test results on the mechanical properties of calcium sulfo-alminous expansive cement concrete conducted prior to the construction works.
Test results showed that 70kg/m³ of the calcium sulfo-alminous expansive agent content results in the self-prestress of 20kg/cm² in the concrete having the unit cement content of 380kg/m³.

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In this paper, the loss in weight and strength (compressive and bending) of cement mortar impregnated with MMA polymer (PIC) and 90% MMA+10% USP polymerized by radiation induced method were examined as compare with plain mortar (control member), in order to make clear their resistance character to chemical attack by 10% HCl, 10% H₂SO₄, 30% H₂SO₄ and 10% NaOH under two temperature status at 20°C and 80°C.
The test results are summarized as follows.
1) At the point of loss of weight and strength, the polymer impregnated concrete PIC have the excellent characters for acid and sulfate attack than the plain mortar.
2) The corrosion of plain and PIC mortar for chemical attack at high temperatures solution (80°C) were greater than the normal temperature (20°C).
3) PIC which the cross linking agent 10% unsaturated polyester (USP) was added in to MMA-monomer has more effects improve the chemical attack resistance than the single MMA-PIC.

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