INFLUENCE OF TANSPORTATION TIME ON PROPERTIES OF ASPHALT MIXTURE IN PAVMENT MAINTAINANCE

Abstract

 This study examines the effects of ambient temperature variations on hot mix asphalt as a function of transportation time, focusing on the temperature ranges pertinent to Addis Ababa City. The objective is to determine the optimal transportation time for hot mix asphalt to enhance the durability of asphalt maintenance works. In a controlled environment, asphalt mixture specimens are subjected to two specific ambient temperatures such as 7 °C and 19 °C to simulate the extreme conditions experienced in Addis Ababa City. Temperature data were collected every five minutes to observe cooling patterns. Additionally, Laboratory tests were conducted using the Superpave Gyratory Compactor and Hamburg Wheel Tracker to evaluate the performance of specimens at varying compaction temperatures of 90 °C, 135 °C, and 150 °C to provide experimental support. Considering the compaction temperature standards of the Addis Ababa City Roads Authority (135 °C) and the loading temperature (160 °C), results showed that Covered specimens can be transported 6 minutes longer than uncovered ones at 19 °C and 3 minutes longer at 7 °C. Furthermore, at 19 °C, covered specimens can be transported 4 minutes longer than at 7°C, while uncovered specimens can be transported 1 minute longer than at 7 °C. Performance tests revealed variations in density and deformation among specimens with the same materials and specifications under specified compaction temperatures. These findings are expected to enhance road maintenance protocols and extend the lifespan of asphalt pavements.