Effect of support type on the fracture toughness and energy of asphalt concrete at different temperature conditions

Abstract

This research deals with the effect of support type on the fracture toughness and fracture energy of asphalt concrete at various temperatures of −20, −10, 0, 10 and 20 °C. Fracture experiments were conducted on the SCB specimens using three different types of support including roller, roller-in-groove and fixed supports. Both the fracture toughness and the fracture energy of asphalt concrete reduced as the temperature enhanced. The results of fracture toughness and fracture energy showed that their values were highly dependent on the type of supports due to existing friction forces at the support boundary conditions. The fixed support type provided the highest values of fracture toughness and energy, and those for the roller-in-groove and roller support types were in the next ranks. From finite element modeling, the friction coefficients of 0.03 and 0.1 were finally found to be suitable to take account of friction effects in the roller-in-groove and fixed support cases. The results also revealed that the fixed support type was not suitable for measuring the fracture parameters of asphalt concrete particularly at the temperatures over 0 °C.