Asphalt stress and cracking temperature measuring device and measuring method

Abstract

The invention discloses an asphalt stress and cracking temperature measuring device and method, the device comprises an axial tension and compression loading frame, a programmable temperature control box is arranged in the axial tension and compression loading frame, and an asphalt test piece is arranged in the programmable temperature control box; a rigid base is arranged at the bottom of the programmable temperature control box, and the bottom of the rigid base is fixedly connected with the inner bottom of the axial tension and compression loading frame; an upper clamp is arranged at the top end of the asphalt test piece, a lower clamp is arranged at the lower end of the asphalt test piece, and a displacement sensor for monitoring the displacement of the upper clamp is arranged on the axial tension and compression loading frame; the bottom of the lower clamp is fixedly connected with the rigid base; the asphalt stress and cracking temperature measuring device disclosed by the invention is used for directly measuring and evaluating the hot cracking property of asphalt. And the cracking stress and the cracking temperature do not need to be indirectly and complexly calculated through a creep test and viscoelastic modeling theory. By adjusting the cooling rate and the geometrical shape of the asphalt test piece, the actual thermal shrinkage condition of the on-site pavement asphalt can be better simulated.

Description

technical field [0001] The invention relates to the technical field of asphalt stress testing, in particular to an asphalt stress and cracking temperature measuring device and a measuring method. Background technique [0002] Many studies believe that the thermal shrinkage effect is the main cause of cracks in asphalt pavement in the early stage of use. The sudden drop in air temperature may lead to the low temperature shrinkage deformation of the pavement, but the friction between the asphalt pavement layer and the base layer will limit the free development of the shrinkage strain. In this case, the pavement tries to maintain its original length, but low-temperature shrinkage stress (tensile stress) has accumulated internally. Fracture occurs when the accumulated low temperature shrinkage stress is greater than the tensile strength of the pavement. The orthotropic response of the pavement structure to temperature drop results in cracks that always develop in the width dir...

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Problems solved by technology

[0007] In view of the above-mentioned problems in the prior art, the present invention aims to provide a kind of asphalt stress and cracking temperature measuring device and measuring method, can provide the thermal average stress-strain condition similar to the field pavement for asphalt in the laboratory, solve The traditional indoor test device for evaluating the low temperature performance of asphalt is difficult to directly test the low temperature strain of asphalt and the test results are inaccurate

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