Polishing aggregates to equilibrium skid resistance

Recent research undertaken by the University of Auckland has clearly shown that the �approximately sinusoidal� effect of the variation in measured skid resistance is neither a repeatable, nor a predictable, phenomenon. If the causal effects are known, this will enable better decision making by road managers which will lead to more appropriate road management in terms of surfacing techniques and practices. The paper reports on Stage 1 of the project that developed a controlled laboratory experiment using the Dynamic Friction Tester, and an accelerated polishing machine to simulate in-field variation of measured skid resistance. The paper discusses the development of testing procedures, methodologies and laboratory equipment and presents results to date in simulating the in-field polishing of road surface aggregates to equilibrium skid resistance levels for a range of high to low PSV aggregates. The experiments were undertaken on prepared chip sealed surface samples that were subjected to cycles of polishing and periodic skid testing. (a) For the covering entry of this conference, please see ITRD abstract no. E212865.