Evaluating the Compressive Strength of Sulfur Mortar in Comparison with Conventional Cement Mortar

The quantity of sulfur produced as a byproduct of the industrial refining process is large because of the fast-growing usage of fossil fuels. The future sulfur levels are predicted to rise steadily, therefore without a counterplan, the high expense of waste management will be necessary. Therefore, in this study, sulfur was utilized as a building ingredient for concrete and asphalt. The purpose of the current work was to evaluate the compressive strength of unmodified sulfur mortar (made with unmodified sulfur binder instead of Portland cement) and compare it to the strength of the cement mortar. Specimens of cement mortar and sulfur mortar with three different percentages of sulfur (30, 35, and 40%) were tested and the results showed that the mortar with 40% of sulfur presented the optimum strength. These four types of mortar were further tested to inspect their properties in severe environments, namely their chemical resistance. In the resistance test, in 30% HCl solution, the cement mortar case demonstrated the most significant mass reduction (19.4%) and compressive strength reduction (83%), whereas the 40% of the sulfur mortar case exhibited the lowest reduction percentages for both the mass (3.3%) and compressive strength (36%). These findings demonstrate that the unmodified sulfur mortar, when optimally proportioned, offers superior performance in aggressive environments, a rapid strength gain, and a viable use for excess industrial sulfur. The study contributes to the sustainable construction material research by providing a low-cost, high-durability alternative to cement mortar, with particular applicability in infrastructure exposed to acids, such as sewage systems, industrial floors, and chemical containment structures.