Effect of Moisture on Durability of HMA used in Roads Adjacent to Waterways.

El-shabrawy, Mohammed; Saafan, Tarek A.; Ibrahim, Mourad H.; Ali, Alaa

doi:10.21608/bfemu.2020.122153

Effect of Moisture on Durability of HMA used in Roads Adjacent to Waterways.

Document Type : Research Studies

Authors

¹ Public Works Engineering Department., Faculty of Engineering., El-Mansoura University., Egypt.

² Irrigation & Hydraulics Engineering Department., Faculty of Engineering., El-Mansoura University., Mansoura., Egypt

³ Public Works Engineering Department., Faculty of Engineering., El-Mansoura University., Mansoura., Egypt

⁴ Public Works Engineering Department., Faculty of Engineering., El-Mansoura University., Mansoura., Egypt.

10.21608/bfemu.2020.122153

Abstract

Studies on the durability assessment have generally been performed to gain Information on the resistance of bituminous mixtures against water. This paper proposes a new technique to investigate the influence of water on Asphalt Mix Durability and hence developing a new criterion for estimating the performance of the HMA used in roads adjacent to waterways through the "Durability Index".
The proposed method involves subjecting standard Marshall HMA samples of both 3-D and 4-C types, which are the most common-used HMA mixes in Egypt, to cycles of time series moisture-Immersion process at 60°C for 6h, 12h, 1day, 3days, and 7days periods to simulate their exposure to water in field. These samples were then tested for stability and percentage of stripping for each individual period. On the other hand, the same procedures and tests were proceed on field cylindrical samples that core-cut from roads adjacent to waterways under different moisture conditions fortest results comparison. Based on selected criteria, a theoretical model that fulfills these criteria was adopted to assess the durability performance of the assigned HMA. This parameter is derived from the "accumulative loss of stability" values along the above-mentioned time series. It was continued up to the minimum required value for stability as per ECP-2010 reached. This criterion is revealed as the "Durability Index" which could be utilized in predicting the future performance and durability of different asphalt mixes intended to be used especially in roads adjacent to waterways.

Keywords