Deformation recovery characteristics of asphalt pavement material on steel bridge decks under nondestructive conditions

Abstract

The composition and properties of high-performance asphalt materials for steel bridge deck pavements are quite different. At present, research on the properties of steel bridge deck pavements mainly focuses on the strength law and damage behavior at the loading stage; however, little research exists on the deformation recovery characteristics of materials during unloading. In order to evaluate the deformation recovery ability of steel bridge deck pavement materials in the unloading stage, the repeated creep and step-load recovery test is herein put forward as an alternative to the deficient creep step-load test. The internal stress and residual strain of three typical steel deck pavement materials—a gussasphalt mixture, an epoxy asphalt mixture, and a stone mastic asphalt mixture—were tested. By comparing the results of CSR test and RCSR test, it is found that RCSR test is more suitable for steel bridge deck paving materials.The recovery modulus under three different creep stress levels was calculated to evaluate the ability of the three materials to drive deformation recovery. At the same time, based on the basic theory of viscoelasticity, the fitting parameters of creep compliance were determined, and the strain recovery rates of three kinds of materials under different interval times were calculated. The results reveal that the recovery modulus of the epoxy asphalt mixture is the largest, about 7 times and 4 times as much as stone mastic asphalt and gussasphalt, respectively, and the self-driving ability of epoxy asphalt mixture is better than that of gussasphalt and stone mastic asphalt. Moreover, within the same time interval, the strain recovery rate of the gussasphalt mixture is the fastest; in 3.6 s, the strain recovery rate can reach 82%.