The effect of moisture on hot mix asphalt – Case of indonesian aggregates

Abstract

Indonesia is a tropical country and has a monsoon season. It is a common problem in major cities of Indonesia, especially in Jakarta, to have a road pavement being damaged after the rainy or monsoon season, especially when the pavements were flooded. This research aims to study the effect of moisture on asphaltic surfaces as designed according to Indonesian standards in order to determine the characteristic of the asphaltic mixture. The results of this study could help in identifying the issue(s) that cause the susceptibility of the asphaltic mixture, and hence, in the future, these issues could be handled better.The samples were prepared by using two different natural aggregates and two 60/70 asphalt binders that were sourced from different producers. There were four sample combinations prepared, which were then tested for Marshall, Cantabro Loss, and Indirect Tensile Strength (ITS) tests. The Marshall test was used to determine the stability and the flow of aggregates, while the other tests were used to determine the impact of water or moisture on the prepared samples. It was found that the samples that were prepared using Aggregate 2 had a higher stability and were more resistant to abrasion load after the samples being immersed in the water for one hour (based on the Cantabro Loss test results) than the samples that were prepared using Aggregate 1. However, from the ITS test results, it was found that the samples that were prepared using Aggregate 2 became “weaker” after being immersed in the water for 24 hours compared to the samples that were prepared using Aggregate 1. This could be due to the fact that Aggregate 2 had a higher percentage of water absorption value, which will place in effect after a long period of time. It did not seem to matter when the samples were being immersed for only one hour. It was also found that the Cantabro Loss and ITS test results had an inverse relationship, which could be due to the difference in the immersion time of both tests.