Azade Najafghlizade - My Institute/Company Tehran, Tehran, Iran
Vahid Hadadi

Shrinkage cracks and rutting in pavement occurs in streets due to temperature changes in different seasons. Filling the cracks with elastomeric bituminous sealants is one of the convenient ways to prevent development of cracks. Low strength and flexibility, incoherence, low stability, lack of resistant against penetration and expensive ingredient are sealant's problems. Therefore, the aim of this study is the modification of sealant to cut down costs, by using waste Sulphur and oily waste bentonite from refining oil factories. The use of waste material, in addition to reducing costs, solves the environment problems. In this investigation, several amounts of Sulphur and oily Bentonite was added to basic sealant material (bitumen 60/70, SBS and talc) and then the rheological, physical and mechanical properties of the blend were studied. It is found that addition of Sulphur to basic mastic causes: 1- High strength and resistance to penetration, 2- High thermal stability, 3- Cross linking and inability to re-melt, 4- promoting G*, 5- improving rutting resistance. It is found that the 160°C temperature is not a suitable temperature for SBS modified asphalt with every percentage of sulphur and in this temperature a gel component may be formed. Addition of oily bentonite besides sulphur to mastic causes: 1- decreasing density, 2- Increasing flexibility, 3- improving G*.

bituminous sealant, sulphur, oily bentonite, physical and rheological properties