Original paper(Vol.48 No.11 pp.1275)

Revaluation of the strength of gas-pressure welded joints used in the existing concrete structural buildings

Tanaka Reiji; Ohaga Yosiki; Kumagai Motoyuki; Ozawa Masahiro

Abstract:The strength of gas-pressure welded joint is evaluated as strong as the strength of the using reinforcement. But, many gas-pressure welded joints were damaged in RC and SRC structural buildings at the 1995 Hyogoken Nanbu Earthquake. After earthquake, we picked up 365 test pieces of gas-pressure welded joints from the damaged RC and SRC structural buildings, and those pieces were tested by the tension test. The 12.6% pieces in all test specimens were fractured. Therefore, the strength of gas-pressure welded joints in the existing concrete structural buildings are not able to apply the present evaluation. This paper is a study on the revaluation of strength of gas-pressure welded joints. The strength of gas-pressure welded joints were revaluated by the research data of Hyogoken Nanbu Earthquake and another test data of 23 public experiment institution in Japan. From the research of this study, we took mainly the following conclusions.
(1) The strength of gas-pressure welded joint used in the existing concrete structural buildings were not evaluated as strong as the strength of the using reinforcement.
(2) We proposed the method of revaluation of the strength for gas-pressure welded joints used in the existing concrete structural buildings.

Key Words:existing concrete structural building, strength of gas-pressure welded joint, 1995 Hyogoken Nanbu earthquake