A kind of asphalt low-temperature ring cracking and freezing disc structure and asphalt low-temperature ring cracking tester

Abstract

The invention discloses a freeze-fracture disc structure for low-temperature ring cracking of asphalt, and a low-temperature ring-crack tester for asphalt. The freeze-fracture disc structure for low-temperature ring cracking of asphalt comprises a base and a no-expansion circle ring, wherein the center of the base is provided with an annular groove, the no-expansion circle ring tightly sleeves the inner ring wall of the annular groove, annular accommodating space for placing asphalt is formed between the outer wall of the no-expansion circle ring and the annular groove, and the outer ring wall of the annular groove is provided with a synapse. Asphalt is heated and poured into an annular area; ambient temperature is allowed to continuously decrease; an asphalt circular ring shrinks and the no-expansion circle ring slightly shrinks, so temperature stress is produced in an asphalt circular ring sample; due to arrangement of the synapse, a fracture point of an asphalt circular ring at low temperature is allowed to be located at the synapse; and the ring crack temperature and ring crack strength of the asphalt circular ring are eventually calculated by detecting the value of temperature variation and stress at the synapse. The disc structure is applied to the low-temperature ring-crack tester for asphalt, and the tester can approximately simulate corresponding maximal fracture stress during fracture of a pavement and correlates the fracture stress with the actual low temperature condition of a pavement mixture.

Description

Technical field [0001] The invention relates to the technical field of asphalt performance evaluation, in particular to an asphalt ring-crack freeze-off disc structure and an asphalt low-temperature ring-crack tester. Background technique [0002] The cracking of asphalt pavement is a common concern of the road community at home and abroad. Its hazard is that moisture can penetrate into the pavement structure along the cracks, so that the pavement base layer and subgrade will soften, the bearing capacity of the pavement structure will decrease, and the road load will produce mud and mud. Scoured, the interface layer appears partially voided, which will eventually lead to cracks and potholes in the road surface, which seriously affects the driving quality of the vehicle and greatly reduces the service life of the road surface. [0003] The cracks of asphalt pavement include load cracks and non-load cracks. The cracks caused by the load are often encountered in some high-grade highw...

AI Technical Summary

Problems solved by technology

[0005] Through the analysis of asphalt low temperature evaluation indicators at home and abroad, the current conventional low temperature indicators still have certain deficiencies in terms of mechanical mechanism, test result discrimination and pavement correlation, and many aspects are not reasonable; SHRP index can better evaluate The low-temperature performance of base asphalt cannot be well evaluated for modified asphalt, and the SHRP index is graded by creep properties. It is believed that creep performance can replace damage performance, but studies have shown that there is a correlation between creep performance and damage performance Not very good

At the present stage, the current low-temperature index cannot make a clear characterization of the low-temperature performance of asphalt, and it is necessary to propose a more simple and intuitive index to evaluate the performance of asphalt

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