Experimental Study on the Tension and Compression Performance of Modified Asphalt Bridge Expansion Joints

Abstract

Under the comprehensive influences of the overall deformation of the whole bridge structure, the repeated moving vehicle and temperature loading, the bridge expansion joint was the weak part of bridge structure. The paper chose a new type of modified asphalt binder to test the elastic recovery performance of the modified asphalt binder under different temperatures. Meanwhile the cycle Marshall stability test and direct tensile test of modified asphalt mixture were conducted. Then, the effects of different temperature conditions on the performance of the modified asphalt binder and the asphalt mixture were analyzed to explain its performance mechanism. The results indicated that: (1) The performance recovery of the special cementing material was affected by temperature. The recovery rate gradually increased with the increasing of temperature. The recovery performance showed some “Time-Temperature†characteristics. (2) Affected by the amount of Oil-stone ratio (33.3%) and the single particle size coarse aggregate, the modified asphalt mixture of the suspended structure type had good recovery performance under all test temperature conditions. (3) The tensile elongation rate of the asphalt mixture was large under the high temperature, and the mixture had a good ability to adapt to the flexible deformation. The research results provided that the modified asphalt binder could be used as the bridge expansion joint material.