Abstract:
The objective of this thesis is to evaluate the asphalt concrete mixtures designed by Marshall mix design method in Thailand, as indicated by volumetric and engineering properties. In this study, the samples of 34 asphalt concrete mixtures were collected from 23 highway construction projects that had been designed by Marshall method. These projects are located in 4 regions of Thailand, covering three different types if aggregate: Granite, Basalt and Limestone. The volumetric properties of these specimens were prepared using the Superpave Gyratory Compactor (SGC). Then the results were compared with the Superpave specifications. The determination of the performance based engineering properties was accomplished by repeated uniaxial loading strain test method. The results of permanent deformation reveal that the properties of all asphalt concrete mixture, including volumetric and engineering properties, consistently satisfy Marshall consideration and meet the serviceability at the heavy traffic level. However, considering the same samples using Superpave criteria, the results reveal that the volumetric properties considerably vary and the level of traffic that the sample can accommodate can be classified in many levels, i.e. 26, 24, and 50 percent of samples fall into heavy, medium and low traffic level category respectively. The results from Superpave method are correlated with the results from permanent deformation tests. It is concluded that the asphalt concrete mixture designed by Marshall mix design method has great variation in quality. So, the findings supports that Superpave mix design method should be used for improving asphalt concrete mixture quality.