Sampling method for disc-process shotcrete flexural toughness testing

Abstract

When a reinforcing mesh (or wire mesh) concrete support structure is adopted in projects of tunnels, side slopes, coal mine tunnels and the like by an injection process, concrete needs to be sampled and tested in order to test flexural toughness of concrete. The method for sampling a round specimen plate (sample) during flexural toughness testing of concrete is based on a new mold (see an attached drawing in an abstract of the description): the round reinforcing mesh (or wire mesh) concrete sample which meets requirements of the disc-process concrete flexural toughness testing can be prepared; the concrete specimen plate dismounting process is simplified, and the damage of dismounting mold to the sample is reduced; and mechanical property of the sample remains consistent with mechanical property of the reinforcing mesh (or wire mesh) concrete support structure in practical engineering to the maximum extent. The application aims to provide a new method for preparing the round reinforcing mesh (or wire mesh) concrete sample for concrete flexural toughness tests at the construction sites of tunnels, side slopes, coal mine tunnels and the like.

Description

technical field [0001] The subject matter of the present invention relates to a method for preparing circular concrete samples by spray molding when concrete structures are used in engineering sites such as tunnels, slopes, and coal mine roadways. Background technique [0002] When using concrete structures in actual projects such as tunnels, slopes, and coal mine roadways, in order to improve the mechanical indicators such as strength and toughness of concrete, materials such as fibers or steel mesh (barbed wire) are often added to ordinary concrete. When specifically measuring the mechanical indexes such as strength and toughness of these added fibers or reinforced mesh (barbed wire) concrete, it is necessary to sample the fiber or reinforced mesh (wire mesh) concrete in the project. And the method of the present invention is exactly designed for getting the circular test piece plate when adopting the circular plate method to measure the concrete flexural toughness test. ...

AI Technical Summary

Problems solved by technology

The former method is similar to using a round box without a cover, but it is not conducive to the removal of the later test piece plate due to the adhesion between the concrete and the side groove of the mold or the bottom plate when the test piece is made, the fixed structure is relatively bulky, and the use of the mold is inconvenient , the key is not to make rigid mesh concrete or barbed wire sprayed concrete specimens; the method of using the latter mold to prepare a circular concrete specimen plate, although an improvement has been made on the basis of the former method, through the mold Improvement, the side groove is divided into two semicircular shapes, and the two semicircular side grooves are fixed with screws, and the two semicircular side grooves are separated by removing the screws, and then the test piece board is taken out

This method works well when taking the pouring-formed circular concrete specimen plate, but when taking the spray-formed specimen plate, because the sprayed concrete is divergent, the side groove is squeezed and it is difficult to fix, and the side groove is splashed. The concrete will block the rotation of the screw, which will increase the difficulty of removing the mold from the test piece plate, and it is also not suitable for rigid mesh concrete or barbed wire sprayed concrete test pieces.

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