Enhanced Performance of Asphalt Mixtures by Adding Recycled Rubber from Damaged Car Tires

Abstract

Due to the problems that the Libyan road network is exposed to, such as cracks and ruts resulting
from increased loads on the roads. Therefore, research and development in this field aims to
improve the properties of asphalt and enhance its performance on roads through the use of
innovative technologies and improved materials. In this research, the properties of asphalt mixtures
modified with rubber resulting from recycling damaged rubber car tires were studied, in order to
improve their performance in terms of stability and flow, which enhances their ability to deal with
expansion and contraction resulting from thermal changes and traffic movement on the roads. The
results showed that when rubber was added to the asphalt mixture, all properties of the asphalt
mixture improved, as the stability value increased by 15.8% when rubber was added, while the
flow value decreased by adding rubber. By 14.5%. The results also showed that the best
percentage of bitumen was 5.6%, and the best percentage of rubber added to the asphalt mixture
was 9%. After extracting bitumen from the modified mixture with 9% rubber, it was found that the
percentage of effective bitumen was 5.9%, which was 0.3% more than the optimum percentage of
bitumen. Therefore, the percentage of bitumen decreased by 0.3% to be within the specifications.
Based on the research results, we recommend using 9% rubber in the modified mixture in the
asphalt mixture industry in Libya due to its benefits on the durability of the pavement, resistance to
rutting, and reducing road maintenance. Adding rubber reduces the costs of road maintenance and
paving by reducing the percentage of bitumen in the asphalt mixture.