Influence of aggregate packing structure and bitumen-aggregate binding characteristic on the mechanistic performance of hot-mix asphalt concrete
Teo, Erwin Kwang Hui.
Date of Issue2010
School of Civil and Environmental Engineering
Centre for Transportation Studies
The Bailey Method was studied as a relatively new approach to blend aggregates and to create a new gradation. It involved using a trial and error method conforming to certain guidelines in the Bailey Method to produce a new mix (W3D1). The Bailey Method stresses on the packing characteristics of aggregates as well as the aggregate interlocking structure. The method provides a set of tools that allows the evaluation of aggregate blends. It gives the designer a better understanding in the relationship between aggregate gradation and mixture voids. The optimum binder content of W3D1 was determined using the Marshall mix design method and it was found to be 5.16%. LTA‟s W3B conventional mix was used as a control with 5.0% optimum binder content. The bituminous binder used was of PEN 60/70 grade and all constituent materials used in this study were within the LTA‟s required standards. Retained Marshall stability tests to determine the moisture susceptibility was performed on the W3D1 blend. The W3D1 blend proved to be much superior in terms of resistance to moisture damage. The W3D1 blend exhibited good resilient modulus results (MR) compared to W3B at 25°C, but the results at 40°C were not definitive. The results obtained in this study suggested that the new W3D1 blend is quite feasible for applying onto pavement construction in Singapore as it can meet the LTA requirements. The W3D1 mix also surpasses the performance of the prevailing W3B blend.
Final Year Project (FYP)
Nanyang Technological University