Search

In the asphalt mixtures, although asphalt is predominantly considered the binder holding the aggregates together, the actual product used to connect aggregate particles is the asphalt-mineral filler mastic which consists of the asphalt and mineral filler. The characterization of asphalt-mineral filler mastic is essential to improve the understanding of the response and performance of asphalt concrete pavements. It is also important to understand the high- and low-temperature properties of asphalt-mineral filler mastic. In this paper, the parameters of the viscous component of the repeat creep stiffness [G.sub.v] were evaluated using a dynamic shear rheometer; and the creep stiffness modulus S was determined using a bending beam rheometer. The effects of filler/asphalt ratios F/A (on a weight basis) on the high-temperature and low-temperature properties of different asphalt-mineral filler mastics were studied. The results showed that the rheological behavior of asphalt-mineral filler mastics are nonlinear, and follow an exponent function model. The curve can be separated into three components: the slowly changing phase, the transitional changing phase, and the fast changing phase. To more easily understand the two straight line models, we calculated the F/A of the inflection point in the curve and determined that the optimal range of F/A is 0.9-1.4 to balance the high-temperature and low-temperature properties from the aspect of interacting models of asphalts and mineral fillers. Furthermore, the approach to get the optimal F/A ratio was discussed. DOI: 10.1061/(ASCE)MT.1943-5533.0000015 CE Database subject headings: Asphalts; Mixtures; Temperature effects; Asphalts; Creep; Stiffness; Material properties. Author keywords: Asphalt-mineral filler mastic; High-temperature and low-temperature performance; F/A (filler-to-asphalt ratio, on a weight basis); Viscous component of the creep stiffness [G.sub.v]; Stiffness modulus S.

To analyze the similarity of stress state between rutting test and asphalt pavement, finite element simulation was carried out to modify the rutting test model based on similarity theory. Firstly, the relationship between structure of asphalt pavement and parameters of the modified rutting test model was deduced through similarity theory. Then the affected areas for three typical pavement structure under loading of wheel load were obtained by finite element simulation with ABAQUS, and the model size of the entire structure was achieved by dint of similarity theory. According to the principle of mechanical response equivalency, parameters of indoor rutting test model for the multiple board structure were determined, and the correctness of multiple board rutting model was verified by rutting test. [ABSTRACT FROM AUTHOR]

To research the coordination between asphalt mixture and fiber Bragg grating sensor (FBG), we used the large-scale finite element software ABAQUS to establish a coordination distortion appraisal model, which was the four-point-bend beam specimen, and analyzed the influence on simulation results with or without a FBG as well as the strain distribution around the sensor at different seal material module, The result indicates that, under the same condition, the existence of high module sensor changes the distribution of stress and strain field, which causes the concentration of horizontal tensile stress around the sensor and reduces the tensile strain at the beam bottom and the changing range of the stress field. The influence on he local region is little, but it is great on the strain distribution of the whole beam; with the increase of the module, the tensile strain at the beam bottom and the changing range of the stress field are decreased gradually while the decreasing rate falls gradually and tends to be stable. [ABSTRACT FROM AUTHOR]