Evaluating the impact of different types of stabilised bases on the overall performance of flexible pavements

Abstract

ABSTRACTThis study was initiated with the aim of evaluating the impact of stabilised and untreated base layers on the performance (i.e. fatigue and rutting) of flexible pavements. Four field sections constructed using stabilised base layers (i.e. bituminous (asphalt emulsion), calcium chloride (CaCl2), Portland cement and geogrid stabilised base layers) and a control section constructed using untreated recycled asphalt pavement (RAP) aggregates were analysed in this study. Falling weight deflectometer tests were conducted on all field sections and the collected data was used to back-calculate the elastic moduli for all layers. The influence of the stabilised bases and the untreated (RAP) base on the mechanical responses (stresses and strains) of the overall pavement structure was also evaluated by conducting layered elastic analyses. In addition, pavement ME design simulations were conducted to determine which of the four stabilised base types enhanced the overall predicted performance of flexible pavements the most. A service life of 20 years was used for pavement ME analysis. Based on the results, it was concluded that the Portland cement-treated base seemed to be more effective than the other stabilised bases at improving the resistance of the pavement sections to fatigue cracking followed by the CaCl2 and bituminous stabilised bases. The geogrid stabilised base appeared to have the least impact on improving fatigue cracking resistance. It was also determined that base layer stabilisation appeared to have little effect on the rutting resistance of the pavement sections.