A method for evaluating the low temperature cracking resistance of asphalt

Abstract

The invention discloses an evaluation method for the low temperature crack resistance of asphalt. The method includes the steps of: taking or preparing a pedestal and a non-expansive circular ring, wherein the middle of the pedestal is provided with an annular groove, the non-expansive circular ring is closely sleeved on the inner ring wall of the annular groove, the pedestal is equipped with a synapse on the outer ring wall of the annular groove, and the synapse is a cylindrical synapse horizontally disposed on the outer ring wall of the annular groove; heating asphalt, pouring the asphalt into an annular space between the non-expansive circular ring and the outer ring wall of the annular groove, and performing cooling molding to obtain an asphalt circular ring; conducting cooling till the asphalt circular ring fractures, detecting and recording the temperature value and the instantaneous strain value of the non-expansive circular ring at a position corresponding to the synapse. The method performs approximate simulation of a corresponding maximum fracture strain during pavement fracture, establishes correlation with the pavement mixture actual low temperature condition, can realize fixed-point fracture, and can measure the strength value of a fracture part specifically. By means of the method, the measured ring fracture temperature has good correlation with TSRST fracture temperature, and the method has good accuracy and repeatability.

Description

technical field [0001] The invention belongs to the technical field of asphalt performance evaluation, in particular to an evaluation method of asphalt low-temperature crack resistance. Background technique [0002] The cracking of asphalt pavement is a common concern in the road circles at home and abroad. The harm is that water will soak into the pavement structure along the cracks, so that the pavement base and subgrade will become soft, the bearing capacity of the pavement structure will decrease, and under the action of driving load, mud will be generated. Scouring, the interface layer is partially voided, which eventually leads to network cracks and potholes on the road surface, which seriously affects the driving quality of the vehicle and greatly reduces the service life of the road surface. [0003] Cracks in asphalt pavement include loaded cracks and non-loaded cracks. Cracks caused by loads are often encountered in some seriously overloaded high-grade roadways in...

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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