The selection of a sprayed seal surfacing suitable for use in accelerated pavement testing with the accelerated loading facility (ALF) is discussed. The design of the sprayed seal surfacing was conducted based on the latest Austroads sprayed seal design method, and consideration was given to aggregate embedment and conversion of ALF load to equivalent design traffic. The selected seal, a double seal with latex modified emulsion binder, was applied using a special process enabling application of binder and aggregate in a single pass. It has been shown that a double/double seal can perform well under high traffic stress, particularly when used with a modified binder suitable for high stress conditions. The relative performance of the seal when placed over a marginal base material demonstrated that it is very difficult to make an appropriate allowance for seal aggregate embedment when using marginal pavement materials under heavy traffic. Based on a limited study, its is suggested that the current ball embedment test used by the design method, may not be sensitive enough to reliably determine an embedment allowance for different fine grained/marginal pavement materials known to suffer embedment. (a) For the covering entry of this conference, please see ITRD abstract no. E217100.
Samenvatting