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

Abstract

[EN] 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.