Testing method for concrete damage fracture performance under double-field coupling

Abstract

The invention relates to a testing method for concrete damage fracture performance under double-field coupling, and belongs to the technical field of physical testing methods. The testing method comprises the following steps: (1) arranging an environmental box, a load frame, a test beam, a preloading device, an acoustic emission detector, a strain measuring device and a load measuring device; (2) applying preload to a three-point bending test beam, maintaining the preload, and adding an environmental simulation solution into the environmental box simultaneously; (3) after the test beam is subjected to the coupling effect of a load and a chemical field, applying a test load F to the three-point bending test beam by a pressure machine through a force applying seat; (4) measuring and calculating the damage degree of the coupling effect of a concrete structure through an acoustic emission rate; and (5) establishing new initial fracture toughness and unstable fracture toughness by combining the coupling damage degree with initial damage. The method provides evaluation and determination for the initial damage of the concrete structure under the effect of environments and loads of actual engineering, and has guiding significance for fracture performance and life prediction for the concrete structure with the 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 of various loads and environmental conditions. Concrete fracture performance

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

Images