Nano-Silica modifier asphalt concrete under rutting resistance and shape memory component

Permanent deformation is pavement distress that has been the root cause of failure of roads globally. With the formation of a rut, follows cracking which inevitably damages the asphalt and sub-base layers. To curb the rutting distress, this study investigates the use of nanosilica, miniaturized silica particles to the power of 10-9 to modify the binder of the asphalt concrete. The nano-silica was added at 4%, 6% and 15% by weight of bitumen into the asphalt mixture. Marshall Mix design method was used to prepare the forty-eight samples used in the study. Repeated Load Permanent Deformation (RLPD) test and Shape Memory (SM) were performed at two temperatures (25°C and 40°C). It was found that the rutting resistance and shape memory had the best performance with the addition of 15% nano-silica at 40°C. Addition of nano-silica at 15% by weight of bitumen had the best amelioration of not only permanent deformation resistance but also shape retention thus enhancing pavement performance.