Evaluation of Moisture and Ageing Effects on Calcium Carbonate Nanoparticles Modified Asphalt Mixtures

摘要

Flexible pavements deteriorate and crack with time due to the frequent traffic load imposed upon it. Many studies have been done to predict the effects of frequent traffic load and environmental conditions on pavements in the effort to find the best pavement design which resist deterioration and ensure longer pavement service time. This study investigates the effect of mixing asphalt with varying percentages of nano calcium carbonate (CaCO_3), namely 0, 2, 4, and 6 %. The mixtures were designed based on the Superpave mix design criteria. Investigation was done using several tests, namely resilient modulus, indirect tensile strength, moisture susceptibility, and dynamic modulus tests. Samples were subjected to aging to determine their resilient modulus. The results of the investigation show that resilient modulus and indirect tensile strength increased when higher percentages of nanoparticles were added to asphalt mixture, with improvement of 138 and 48.18% respectively. Modified binders showed up to 17% improvement in moisture susceptibility comparison to base asphalt mixture, while the result of dynamic modulus test showed that the stiffness of modified asphalt increased 76.69%. The investigation also found that adding 6% CaCO_3 nanoparticles to asphalt produced modified asphalt with the best performance. In addition, the results show that the modified asphalt with CaCO_3 is suitable for hot and humid regions (tropical countries) in the field of highways construction, as the modifier was able to mitigate the influences of high-temperature rutting and moisture damage.