The Influence of Ageing on Asphalt Mastic Properties Incorporating Calcium Carbonate

Abstract

The ageing of asphalt mastic is one of the key factors determining the lifetime of an asphalt pavement. The challenge created by proper selection of asphalt materials motivate researchers to investigate material properties that can further enhanced performance of asphalt pavement. The study investigated the ageing properties of asphalt mastics incorporating calcium carbonate (CaCO3) combined with Ordinary Portland Cement (OPC). The empirical tests, which include penetration and softening points, were conducted to ascertain the asphalt mastics consistency. The rheological properties of mastics in terms rotational viscosity and Superpave rutting parameter using 60/70 asphalt binder blended with 5, 10, 15, 20 % of CaCO3+OPC were calculated to evaluate asphalt mastics properties subjected to different aged conditions. Rotational viscometer (RV) was used to evaluate the properties of mastics. The dynamic shear rheometer (DSR) was used in temperature sweep test to measure the complex modulus (G*) and phase angle (δ). ANOVA statistical analysis was used to analyze the results .The test results showed that all asphalt mastics exhibited higher viscosity compared to the base binder. The addition of various content of CaCO3+OPC increased the G* and decreased the δ significantly, indicating an increase in binder elasticity and stiffness, hence a better resistance to deformation.