Studying The Application of Thiopave and Thiocrete Technology in Egypt

Abstract

With development of gas processing refineries in Egypt, the current and anticipated future production of sulfur would increase sufficiently to provide substantial quantities of modified sulfur in asphalt paving mixtures and to permit full dependence on sulfur in concrete industry especially in aggressive media. The aim of this work is to avoid all problems associated with the handling, and durability of sulfur, as well as the toxic emissions produced from elemental sulfur during its conversion to more stable modified one by mixing the elemental sulfur with the combination of byproducts of olefinic hydrocarbons and cyclic hydrocarbon bituminous residue at 150oC . The changes in the structural characteristics and morphology of the prepared modified sulfur were studied using XRD and SEM respectively. Moreover, DSC curves are developed to elucidate the changes in sulfur phases from α-orthorombic to β-mono clinic structure. The technique of nanoindentation is utilized to compare the mechanical properties of modified and pure sulfur including modulus of elasticity and hardness. Asphalt binder in pavement is substituted by the modified sulfur (Thiopave) by 20wt%, 30wt%, and 40wt% to give three mixtures 20/80 S/A, 30/70 S/A, and 40/60 S/A respectively. Beside the conventional tests, SUPERPAVE binder specifications are conducted on sulfur/asphalt binders. Furthermore the hot mixtures asphalt designs are prepared according to Marshall method. The mechanical properties of the designs are measured including Marshall Stability, Flow, Air voids, and Marshall Stiffness.

Results obtained from this study indicated that THIOPAVE increases the overall mixture strength, and achieve an improved load bearing capacity of the finished road. In addition, Thiopave enables the asphalt to achieve compaction at a considerably lower temperature when compared to base asphalt binder. Thiopave also enables lower temperature production, delivering meaningful reductions in greenhouse gas emissions. This allows the compound to cool and harden quicker and helps reduce the chance of thermal cracking even in adverse weather conditions. Similarly, the modified sulfur is applied in concrete industry as a cementing material instead of Portland cement (THIOCRETE). The mechanical properties, durability, and corrosion resistance of sulfur polymer concrete (SPC) mortars are studied. Results reveal that (SPC) show higher strength, better durability towards acid media and sea water environment, and higher corrosion resistance than Portland cement concrete mortars (PPC).