This report describes the progress of rehabilitation trials using polymer modified strain alleviating membrane treatments to prevent reflection cracking. The trials were initiated to provide quantitative performance based information on a range of proprietary products and bitumen scrap rubber modified binder. The methodology used involved trials of the various products on homogeneous sections of cracked but structurally sound pavement where the cracking was caused by environmental rather than load associated movement. Test properties were determined for all products except composite treatments that combined binders with reinforcing fibre materials. Reflection cracking was monitored regularly to provide information that regularly to provide information that could be used to relate product properties to performance. The results of the trials after 42 months service indicated there was a significant difference in performance between products. The best results were achieved on sections utilising either a lightly modified binder or unmodified class 170 bitumen. Both exhibited very little reflection cracking. More heavily modified binder gave a higher level of reflection cracking. There is no clear relationship between material test properties and performance and research is required to develop better predictors of performance. (A)
Abstract