Method for measuring interlocking capability of coarse aggregate

Abstract

The invention relates to a method for measuring the interlocking capability of coarse aggregate, belonging to the technical field of road material design evaluation. The method comprises the following steps of: (1) filling coarse aggregate gravels into a rigid test barrel and ramming the coarse aggregate gravels; (2) penetrating a conical rigid squeeze head into the gravels at a certain loading speed rate, and recording a penetration depth H and a squeeze force (resistance) F suffered by the rigid squeeze head; and (3) working out a penetration power W0= the integral of Fdh from 0 to H so as to evaluate the interlocking capability of the coarse aggregate. The method evaluates the interlocking capability of the coarse aggregate grading gravels by adopting the conical squeeze head penetration test, and effectively avoids the defects in the original test methods, i.e., aggregate mixing ratio is changed and real properties of design grading can not be correctly reflected due to serious aggregate breakage in the pressing-in process. In addition, the method takes energy indexes in terms of material deformation and stress into full consideration, adopts the penetration power to evaluate the interlocking capability of the coarse aggregate and more fully reflects the whole properties of the material when compared with simpler deformation index.

Description

technical field [0001] The invention mainly relates to the field of road engineering design and construction, in particular to a method for testing the embedding ability of a coarse aggregate skeleton. Background technique [0002] The strength of asphalt mixture mainly comes from two aspects: one is the cohesive force of the mixture formed by the cementing ability of asphalt to the mineral materials, and the other is the internal friction force formed by the mutual embedding of the mixture and mineral materials. For coarse aggregate dis-graded asphalt mixture, the intercalation ability of coarse aggregate with a particle size greater than 4.75 mm has a significant impact on the strength of the mixture. [0003] Although the "embedding" ability is not a mechanical index in the strict sense, it is very important for the accumulation structure of granular particles. The mutual "occlusion" between skeleton coarse aggregate particles is one of the important factors affecting th...

AI Technical Summary

Problems solved by technology

The mutual "biting" effect between the skeleton coarse aggregate particles is one of the important factors affecting the shear performance of asphalt mixture. Although there is a general consensus on this, there is still no quantitative index for objective evaluation.

In the past, some studies have indirectly evaluated the intercalation ability of coarse aggregates from the perspective of resistance to deformation, such as the classic CBR method and uniaxial penetration method. Due to the large amount of aggregate fragmentation in the experimental process, these two methods cannot Distinguish the strength of the aggregate itself from the shear resistance formed by the embedding. In the actual working state of the asphalt pavement, the damage of the pavement is not caused by the crushing of the aggregate, but due to the insufficient embedding between the aggregates. Due to the change in particle position

Therefore, these two experimental methods are unreasonable as evaluation methods of asphalt mixture skeleton strength.

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