Asphalt mixture fatigue test method based on DCT (Disk-Shaped Compact Tension) and HD (High Definition) imaging technology

Abstract

The invention discloses an asphalt mixture fatigue test method based on a DCT (Disk-Shaped Compact Tension) and HD (High Definition) imaging technology, which comprises the following steps of: preparing a test piece, whitening the side surface of the test piece, gridding according to a certain distance, installing the test piece in a loading clamp and connecting the test piece with a vertical transmission shaft of a MTS (Material Testing System) fatigue machine; debugging a MTS after the test piece is installed and tested and starting a preset fatigue program; testing the maximum damage load of the test piece through a DCT (Discrete Cosine Transform) experiment and then regressing a fatigue equation through different stress ratios and fatigue frequencies corresponding to the stress ratios to evaluate the fatigue performance of materials; and loading a HD video camera on the opposite side of the test piece in the determination, connecting loading frequencies with a digital display counter together within the field of view of the high-definition video camera, simultaneously shooting the change of a distance between two fixed points in a picture during passing the different times of loading and researching the crack width development to obtain a relation between the loading frequencies and the crack extension length and the crack extension speed.

Description

technical field [0001] The invention belongs to the technical field of highway asphalt pavement laboratory simulation test, and relates to a new test method related to the fatigue performance of asphalt mixture. It specifically relates to an asphalt mixture fatigue test method based on DCT and high-definition image technology. Background technique [0002] In recent years, with the vigorous development of my country's highway industry, asphalt pavement has been widely used, and the durability test method (mainly fatigue test) of asphalt pavement materials has always been a hot spot in the field of highway research. At present, there are many testing methods for fatigue performance of asphalt mixture at home and abroad, including trabecular fatigue test, direct tension test, APA fatigue test, field wheel load test, etc. The trabecular fatigue test is the most commonly used experimental method in the laboratory. It is divided into three-point loading and four-point loading. A...

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Problems solved by technology

The trabecular fatigue test is the most commonly used experimental method in the laboratory. It is divided into three-point loading and four-point loading. Although it can simply predict the fatigue performance of asphalt mixture, it can only characterize the two-dimensional stress state of the material, and The fatigue life of the asphalt mixture is underestimated. At the same time, the trabecular fatigue test is an indirect tensile fatigue test, which cannot fully simulate the actual stress state of the asphalt mixture during use; the direct tensile test must be carried out with special rubber at the end Bonding, the experimental process is cumbersome; the APA fatigue test is an indoor wheel load test, although it can simulate the field, but the fatigue of low-stiffness asphalt mixture is easily affected by rutting; although the on-site wheel load simulation can directly determine the actual wheel load Fatigue response, but high cost and long cycle

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