At present the majority of the mass-produced housing structure in Japan is of reinforced concrete wall construction. The buildings utilizing this structural system, including precast panel construction, had been limited to four stories or less until several years ago. This report discusses the four tests on full-size housing structures which were carried out to provide data for making a rational structural design of higher structures.

All of four tests are performed on full-sized, 4 or 5-story housing structures of reinforced concrete wall construction. They were tested statically up to collapse in horizontal direction and some supplemental forced vibration tests were carried out.The first project carried out in 1967 was the test on a 5-storied housing structure of precast reinforced concrete. The objectives of this test are to realize the 5-storied one by general code and to pursue the possibility of improved structural economy. A general recommendation for the structural design of five-storied building has been recently completed. Based upon the results of this test, the quantity of reinforcing bars and concrete were reduced significantly.

The second project carried out in 1968 was the test of an apartment house of reinforced concrete wall construction. The main objective of this experiment was to determine the minimum values of wall thickness and wall length in case of five-storied buildings. From the results of this test, it became clear that the structural regulations which are used for structures lower than 4-stories can be also used for the 5-story ones.

The third project, a test on a 4-storied housing structure of precast reinforced concrete assembled with post tensioning method, was carried out in 1969. This structural system was developed at B .R .I. The main purpose of this test was to obtain data for the design of 8-storied buildings utilizing this system. Success of this test resulted in realization of these size buildings and in the near future 10-storied ones are expected to be built.

The last test, accomplished in 1970 was of an apartment housing structure built with discontinuous reinforced concrete wall construction. The main objective was to investigate the safety of a building which is shifted both horizontally and vertically.The results are now under analysis.