Laboratory evaluation of the mechanical properties of asphalt mixtures with rubber incorporated by the wet, dry, and semi-wet process

摘要

The dry process as well as the wet process used to add rubber to asphalt mixtures have certain drawbacks. For wet process (WP) expensive equipment is needed, while dry process (DP) requires long digestion times to achieve acceptable results. This appears to have produced a stagnation in the development of this technology. The development of predigested rubber has opened the possibility to use this technology, in a process called semi-wet (SWP) that maintains the benefits offered by rubber without the disadvantages of the other two processes. This article presents a comparative study of the mechanical behavior of asphalt mixtures with rubber added by three different processes. For the dry and the semi-wet process two sets of specimens were manufactured, the first set with no digestion time, and the second set with 30 min of digestion time. The results showed that after 30 min of digestion time, the DP mix continued to show an inferior behavior compared to the SWP mix with the same digestion time, especially regarding moisture sensitivity. The results also showed that the SWP mix with 30 min of digestion time maintained and even exceeded the results obtained by the WP mix. (C) 2019 Elsevier Ltd. All rights reserved.