Method for testing fatigue damage of inorganic binding material stabilizing material

Abstract

The invention discloses a method for testing the fatigue damage of an inorganic binding material stabilizing material, and belongs to the field of road engineering. The method comprises the following steps of: cutting a vibration moulding large beam test piece serving as matrix into a plurality of small beam test pieces which meet the specification, determining the fatigue load of the small beam test pieces on the same layer through the bending strength test of the small beam test pieces on the same layer, performing four-point bent beam dynamic repeat load test on the basis, measuring the central deflection change of small beams in the test process to obtain the decay law of dynamic bending modulus along with fatigue load frequency in the approximately actual stress state, and the growthlaw of the bending stress along with the fatigue load frequency, and performing the repeat load test under the conditions of different stress ratios according to the method to obtain the fatigue damage life of the inorganic binding material stable broken stone material. Compared with the conventional fatigue test method, the method overcomes the technical problems of large fatigue failure load frequency variation and low reliability of a fatigue equation in the conventional fatigue test method, realizes the accurate estimation of the fatigue life of the inorganic binding material stable broken stone material, discloses the fatigue damage law of the inorganic binding material stable material, improves the reliability of road design and has good popularization and application value.

Description

technical field [0001] The invention relates to the field of road engineering, in particular to a method for testing fatigue damage of inorganic binder stabilized materials. Background technique [0002] In my country's high-grade highways, semi-rigid base materials are widely used, but engineering practice shows that the early damage of semi-rigid base is serious. In the design and evaluation of the laboratory, the semi-rigid base material only uses simple indicators such as material composition, compressive strength, and static modulus as design standards, and does not conduct in-depth damage evaluation and dynamic mechanical response indicators and parameters that are consistent with the actual stress state of the road surface. test. The existing simple fatigue test method attempts to represent the bending and tensile strength of a part of the beam specimens formed in the same batch as the average value of the bending and tensile strength of this batch of specimens, and ...

AI Technical Summary

Problems solved by technology

Due to reasons such as loading, molding, and health preservation, the bending and tensile strengths of beam specimens of the same batch are not exactly the same. The damage phenomenon is common, which makes the stress concentration during the loading process, which causes the fatigue test data to vary greatly, and it is impossible to obtain accurate and reliable test results. This is also the reason why the existing fatigue test methods for inorganic binder stabilized materials are difficult to implement.

Another important problem is that the existing fatigue test methods only have two parameters, the stress ratio and the number of fatigue loadings, and it is impossible to know the changes in the physical and mechanical responses of the dynamic flexural modulus and flexural strain of the specimen during repeated loading, let alone Evaluating the Fatigue Damage Variation Characteristics of Materials from the Variation Rules of Specimen Parameters

Therefore, the fatigue damage mechanism and dynamic response characteristics of semi-rigid materials have not been clarified and verified, and the damage problem has always puzzled engineers and technicians in my country.

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