Experimental investigation of bituminous plug expansion joint materials containing high content of crumb rubber powder and granules

Bituminous plug expansion joint materials containing high content of crumb rubber powder and granules were investigated. 20 wt% crumb rubber powder was added into SBS modified bitumen to produce a blended binder. Rheological test, which was done by a dynamic shear rheometer (DRS), demonstrated that this blended binder exhibited good performance at high and low temperatures. The replacement of part of mineral aggregates by rubber granules allowed preparing more flexible joint materials. Combining the data obtained from wheel-tracking rutting test and three-point bending test, it was found that 9.2 vol% rubber granule was the critical content for rutting resistance at high temperature and flexibility at low temperature. It was concluded that bituminous plug expansion joint materials containing high content of crumb rubber powder and granules performed well to deal with thermal and traffic loads.