Test method for damage and fracture performance of concrete under double-field coupling

Abstract

The invention relates to a method for testing the damage and fracture performance of concrete under double-field coupling, and belongs to the technical field of physical testing methods. The method includes the following steps: 1) setting an environmental box, a load frame, a test beam, a preloading device, an acoustic emission acquisition device, a strain measuring device and a load measuring device; 2) the preloading device bends the beam to the three-point test beam Apply and maintain the preload FY, and at the same time add an environmental simulation solution to the environmental box; 3) The test beam is coupled with the chemical field, and the press applies the test load F to the three-point bending beam test beam through the force application seat; 4) ) Calculate the coupling damage degree D0 of the concrete structure through the acoustic emission rate; 5) Combine the initial damage to establish a new crack initiation toughness and instability toughness. The evaluation and determination of initial damage has guiding significance for the fracture performance and life prediction of concrete structures with initial damage.

Description

technical field [0001] The invention relates to a method for testing the damage and fracture performance of concrete, belonging to the technical field of physical measurement. Background technique [0002] At present, one of the main methods to study the fracture performance of concrete is to test the three-point bending beam with notch, which is also the mainstream test method to obtain the fracture parameters of concrete (mainly including toughness, fracture energy, etc.). [0003] There is a standard industry regulation DL / T5332-2005 "Hydraulic Concrete Fracture Test Regulations" in the industry. On this basis, there have been a lot of experimental research on three-point bending beams with standard sizes, non-standard sizes, and steel bars. There are corresponding theoretical and empirical formulas. The method of this industry regulation only needs to measure the opening displacement and load of the crack opening to calculate the fracture parameters. The experimental p...

AI Technical Summary

Problems solved by technology

[0007] 3. The tip of the structural crack in the actual project is always under the load, and the continuous load will produce micro-cracks, especially at the tip of the crack. The action of the continuous load will cause a large concrete plastic zone, and its fracture performance will be reduced. will reduce

[0008] 4. The frequency of concrete cracks in actual engineering is very high, and the structure in actual engineering is often under the coupling effect of various loads and environmental conditions

The "Hydraulic Concrete Fracture Test Regulations" does not provide a fracture test performance device under the complex environment and load coupling

Images