Amongst other surface characteristics, the levels of macro-texture on New Zealand State Highways are measured and assessed by a laser device that measures surface texture in both wheel paths and between wheel paths. This paper suggests the data can be used for chip seal design purposes. It reviews analysis of laser measured and sand circle measured texture levels and the relative effect of changes in texture on the calculated residual binder application rate used for chip seal application. It finds the relative precision of the laser measurements is adequate for chip seal design purposes. The difference between the two assessment methods is negligible in its effect on the resultant calculation of binder application rates. The use of laser texture measurements is more representative than sand circle measurements, with minimal risks associated with data management and the physical risk to staff, associated with performing measurements by sand circle methods, also considerably reduced. This procedure has been successfully used on Transit New Zealand's Coastal Otago Hybrid Maintenance Contract chip seal programme for the past two years to check traditional sand circle texture measurements. (a) For the covering entry of this conference, please see ITRD abstract no. 0612AR242E.
Samenvatting