ROAD TRIALS OF AGGREGATE BLENDS FOR CHIPSEALS

The viability of blending high polished stone value (PSV) sealing chips with standard chips in two-coat seals and void fills was investigated, with particular emphasis on their physical performance with respect to abrasion and skid resistance. Laboratory tests and on-road trials were carried out to investigate these properties, with the aim of identifying the most appropriate method of measuring abrasion, and establishing whether such blends would perform well physically and provide the desired levels of skid resistance. The results show that such blends have stood up physically over the relatively short time they have been laid, and that they have also provided a level of skid resistance over that time which is much greater than that specified in Transit New Zealand's T/I0 specification. However, the road trials have not been down long enough to determine either the life of the surface due to abrasion or aggregate breakdown, or whether the skid resistance of the blends will stabilise to acceptable values. (a)