The present disclosure relates to a modified bitumen composition comprising: (a) at least two refinery residues; and (b) a sulphur additive comprising: (i) sulphur; (ii) at least one H.sub.2S suppressant; (iii) at least one smell masking agent; and (iv) bitumen, wherein the sulphur and the at least one H.sub.2S suppressant is in the weight ratio range of 4:1 to 100:1. The present disclosure also discloses a process of preparing a modified bitumen composition and a process of preparing an asphalt pavement comprising a modified bitumen composition. Also provided herein use of a modified bitumen composition as an additive for waterproofing and road construction.

A modified bitumen composition includes bitumen, biomass oil including one or more phenolic compounds, and added sulfur. The modified bitumen composition includes between about 5 wt % and about 25 wt % of the added sulfur, at least some of the added sulfur is present as polysulfide chains, and at least some of the one or more phenolic compounds are configured to covalently bind to the polysulfide chains. Making a modified bitumen includes combining bitumen and elemental sulfur to yield sulfur-extended bitumen, and combining the sulfur-extended bitumen with biomass oil including one or more phenolic compounds to yield the modified bitumen.