Research on the effects of sulfur on characteristics of sulfur bituminous binder (SBB) and hot mix asphalt – sulfur (HMAS)

Sulfur in SBB has been found to occur in three different forms: (1) chemically bonded, (2) dissolved in bitum, and (3) crystalline sulfur which generally exists in the form of discrete tiny particles dispersed in asphalt depending on sulfur content was added to bitumen, mixing temperature and time of a given mixture. At extraction temperatures (20 and 50oC), sulfur crystallizes and acts as a filling agent. It organizes the structure of the asphalt concrete and increases the thermal stability, hardness, and resistance of asphalt concrete to rutting. Due to the progressive restructuring of the modified sulfur in the mixture, the paving mixture made with modified sulfur takes several days to develop its final strength. This paper investigates the effect of time on the properties of SBB and HMAS. Experimental results show that by the time, the crystallization of sulfur in SBB has effects on SBB properties (penetration, softening temperature) and HMAS properties (Marshall stability, Marshall flow)