Cracking in specialist surfacing systems

Specialist surfacings such as high-friction and coloured traffic-calming surfaces have gained huge popularity since their introduction. However, the reputation of these specialist systems in New Zealand is also plagued by premature failures due to cracking and other related modes. Many of the failure modes have in fact originated from or are at least associated with the performance of the underlying pavement substrate. The purpose of this project was to assess test methods where the emphasis was on the performance of the underlying substrate and its interaction with the specialist surfacing systems to ensure best outcomes. A number of commercial resin systems, namely epoxy, polyurethane and methyl methacrylate were tested using methods based on ASTM standard test methods C1583-13 and D638-10. Thermal effects were also investigated by conducting thermal cycling experiments. The intention was to develop a test that could be implemented in the field. As a result, a draft test specification has been developed as part of the research work to better understand the performance of the surfacing systems and their underlying substrates to minimise some of the common premature failures.