Testing method for dynamic modulus of bituminous mixture

Abstract

The invention discloses an indoor testing method for dynamic modulus of a bituminous mixture. The method comprises the following steps that 1, a track forming instrument is used for manufacturing a track plate, and trapezoidal test pieces of the fixed size are cut out from the track plate; 2, the lower bottoms of the trapezoidal test pieces are fixed to a base, the upper bottoms are fixed to a protecting crown, and the test pieces are placed at the testing temperature for heat preserving for at least 4 hours; 3, two testing pieces fixed well in one group are taken and installed onto loading equipment, the base is fixed, the protecting crown is connected with a horizontal loading rod, and the loading rod exerts continuous sine horizontal loads at different frequency and strain levels on the tops of the test pieces; 4, in the loading process, corresponding stress and strain parameters are collected, and the dynamic modulus is calculated. The trapezoidal test pieces are used, the single-point loads are exerted on the ends of the test pieces, bending, pulling and shearing comprehensive stress is generated in the test pieces, real stress situation of a pavement structure can be effectively simulated, the principles are advanced, and the testing method is easy to operate and convenient to popularize.

Description

technical field [0001] The invention belongs to the technical field of road engineering and relates to a new method for indoor testing of dynamic modulus of asphalt mixture. Background technique [0002] Asphalt mixture has typical viscoelastic properties, and its mechanical properties are affected by temperature, frequency, load level, etc. The commonly used static modulus is not enough to describe its mechanical behavior, and the dynamic modulus can better describe its dynamic characteristics. Although many roads are currently designed and constructed according to the current norms and requirements, they are still prone to early damage and cannot meet the requirements of long-life use, which shows the insufficiency of the existing design system. Therefore, it is necessary to conduct a comprehensive study on the dynamic modulus of asphalt mixture. [0003] The commonly used laboratory test methods for the dynamic modulus of asphalt mixtures include uniaxial compression, i...

AI Technical Summary

Problems solved by technology

The specimen size of the uniaxial compression method is relatively large, it cannot be directly selected from the pavement structure, and it is difficult to directly guide the physical engineering, and the force mode is simple, which is inconsistent with the force of the actual pavement; Edge stress concentration is prone to local damage, and the test cannot be carried out at high temperature, the operation is complicated, and the experimental ability is limited; the deformation value of the specimen measured by the four-point bending method is relatively stable, but the test period is long, the force is single, and the cost is high

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