Study on Type II Shear Failure Mechanism of Reinforced Concrete

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As has been mentioned in the proposal document, this research aimed at the clarifying the post peak behavior of reinforced concrete structural failure in the shear mode (we call this type of failure as the shear failure mode of the second type) and the failure velocity in the failing stage. The first step was to develop computer programs which can catch the shear failure mode in the post peak stages. Though we have encountered many difficulties in dealing with the complexity of constitutive equations in the tangential state and the treatment of reinforcing materials and its amalgamation to find out the critical state of acrostic tensor, we have succeeded in developing the 2D finite element programs.In the second stage, we have developed the testing apparatus to perform the shear failure tests of wall type structures. Since all the machine parts are designed by the researcher, it was completed with relatively low expenditure. It was now installed in the Yamanashi University, concrete laboratory, which shared the project in the experimental portion. The testing machine has the special feature that it can maintain the horizontally of rather long top edge line of structural specimens while giving horizontal load as well as vertical load to specimens. Using the apparatus, we have succeeded to give rise to the shear failure mode of second type for the orthogonally reinforced wall specimen as anticipated by the theory.This means that we have succeeded to estimate the failure mode of this type for other structural elements more generally.For the second aim of this project was to clarify the failure velocity of shear failure. In this regards, we have developed the theoretical formulation in the similar way as shock failure prediction.All these research results are published or to be published as listed in the same document.