Real scale evaluation of vibration mitigation of sub-ballast layers with added tyre-derived aggregate

This paper represents a final stage in the assessment of granular sub-ballast materials mixed with tyre derived aggregate (TDA) without binder material. The objective is to evaluate such mixtures through a full-scale test under real traffic conditions. An experimental track with three 30-metre long sections was constructed: one section was built with conventional sub-ballast; and the other two sections were built with mixtures containing increasing rubber content. This track was then monitored using accelerometers. The results show a clear reduction in the acceleration peaks as rubber content increases. Moreover, the excited frequency bandwidth tends to become narrower and shifts to lower frequencies. (C) 2018 Elsevier Ltd. All rights reserved.