Method for measuring and representing microcosmic interface phases of asphalt concrete

Abstract

The invention discloses a method for measuring and representing microcosmic interface phases of asphalt concrete. According to the method, a small asphalt concrete piece is wrapped with epoxy resin AB glue and cured into a flat cylindrical test piece in a mold to prevent the small asphalt concrete piece from being stripped and deformed in the follow-up polishing process and improve the polishing flatness; the test piece is polished with metallographic abrasive paper, and then a final test piece meeting the requirements is obtained after ultrasonic cleaning is performed on the test piece when polishing is completed; the test piece enters a measuring step, all surface phases of the test piece are observed through amplification with a nanoindentation instrument, a measuring region containing all the phases is selected, equally-spaced dotting measuring is performed, and a load-displacement curve and a microscope image are recorded; after the test is finished, the Young modulus and hardness of all the points are computerized according to the load-displacement curve, and then the modulus and hardness indexes of all the phases are obtained by combining the phases where the measured points are located; finally, the size and the mechanical characteristics of a microcosmic interface transition area between asphalt and aggregates in the test piece can be analyzed and estimated according to the changing condition of the distance among the measured points and the mechanical indexes.

Description

technical field [0001] The invention belongs to the technical field of highway asphalt pavement, and specifically relates to a method for testing and characterizing the microscopic interface phase of asphalt concrete, which is used to characterize the multiphase behavior of asphalt mixture (aggregate phase, asphalt mortar phase, interface phase) from a microscopic perspective. Especially the mechanical properties of the interfacial phase, to help researchers connect with the macro from the micro to a deeper understanding of the macro performance of asphalt concrete, and to solve related controversies and practical engineering problems. Background technique [0002] 1. Microscopic properties of asphalt concrete [0003] Asphalt concrete is a composite material composed of asphalt, aggregate, mineral powder, etc. It has excellent road performance, so it is widely used in road paving. The road performance of asphalt concrete is mainly affected by its mechanical properties. How...

AI Technical Summary

Problems solved by technology

However, the nanoindentation test has extremely strict requirements on the production of samples, and it was rarely used in the field of asphalt in the past. Therefore, there is currently no feasible and standardized method for preparing test samples for asphalt concrete.

In addition, nanoindentation is theoretically only suitable for conventional hard materials, and asphalt concrete is a viscoelastic material, and its viscoelasticity will affect the collection and calculation of the load-displacement curve, which will lead to the failure of the test

Therefore, there is no reliable test plan for the application of nano-indentation technology to determine the microscopic properties of asphalt concrete and to deeply characterize the mechanical properties of its interface phase.

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