Evaluation method

Abstract

This evaluation method comprises: a first step S101 for obtaining stress σP0 which is applied to a reinforcement bar in a state where no deformation exists in prestressed concrete produced by imparting prestress P to the reinforcement bar; a second step S102 for obtaining a deformation amount L1 acquired when a crack occurs by deforming, with a load, a test body of the prestressed concrete produced by imparting the prestress P to the reinforcement bar; and a third step S103 for obtaining the relationship between the deformation amount of the test body and stress applied to the reinforcement bar from the prestress P, the stress σP0, and the deformation amount L1, supposing that, in a state where the crack occurs, the prestress P is applied to the reinforcement bar in the test body.

Claims

1. Prestressed concrete, prepared by applying prestress P to the reinforcing bars, is considered an elastic body composed of the reinforcing bars placed within the concrete, and the stress σ on the reinforcing bars when the prestressed concrete is undeformed is calculated. P0 The first step in finding this, The amount of deformation L when a load is applied to a prestressed concrete test specimen, which was prepared by applying prestress P to the reinforcing bars, and cracks occur. 1 The second step in finding this, When cracks occur, a prestress P is assumed to be applied to the reinforcing steel, and the prestress P and stress σ are calculated. P0 , and deformation amount L 1 The third step is to determine the relationship between the deformation of the test specimen and the stress on the reinforcing steel, The fourth step is to evaluate the stress on the reinforcing steel in the prestressed concrete being evaluated based on the relationship obtained. An evaluation method comprising the following features.

2. In the evaluation method described in claim 1, Let E be the modulus of elasticity of the reinforcing steel. The elastic modulus of concrete is E c year, The number of reinforcing bars N p year, The cross-sectional area of ​​one reinforcing bar is A P year, The cross-sectional area of ​​the prestressed concrete is A c year, Let the modulus of elasticity of concrete be E C and The stress σ is given by the following equation (A) P0 To seek An evaluation method characterized by the following. [Math 1]

3. In the evaluation method described in claim 1, The aforementioned test specimen and the prestressed concrete to be evaluated are composed of tensioned reinforcement with prestress P applied to the reinforcement and untensioned reinforcement without prestress P applied to the reinforcement. Let E be the modulus of elasticity of the reinforcing steel. The elastic modulus of concrete is E c year, The number of muscles to be tensed is N p year, The number of non-tonic muscles is N s year, The cross-sectional area of ​​one tension muscle is A P year, The cross-sectional area of ​​one non-tonic muscle is A s year, The cross-sectional area of ​​the prestressed concrete is A c year, The elastic modulus of concrete is E C as, The stress σ is given by the following equation (B) P0 To seek An evaluation method characterized by the following. [Math 2]

4. In the evaluation method according to any one of claims 1 to 3, The aforementioned test specimens and the prestressed concrete to be evaluated are in the form of columns. The second step involves applying a load in a direction intersecting the height direction of the column. An evaluation method characterized by the following.

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