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CONCRETE TECHNOLOGY44 CPI %u2013 Concrete Plant International %u2013 2 | 2026 www.cpi-worldwide.comConventional cement concrete is susceptible to chemical attack and corrosion due to the presence of moisture and aggressive ions such as chlorides and sulphates, which can lead to cracking, spalling, and structural degradation over long-term service. In this study, sulfur was employed as an alternative binder to eliminate hydration-related corrosion risks, since it has been proven to be hydrophobic, while hematite was used as a functional aggregate substitute to further enhance its durability. The prepared sulfur-based specimens were immersed in simulated corrosive environments for 90 days to evaluate their long-term chemical stability. Remarkably, the specimens retained nearly their original mechanical strength, showing no visible surface deterioration. These findings confirm that sulfur-based concrete presents exceptional resistance to corrosive environments, offering a promising and sustainable alternative to conventional cementitious materials, especially for applications in harsh or chemically aggressive conditions such as coastal, industrial, or extraterrestrial environments.In today%u2019s industrial field, petroleum stands at the middle of countless economic activities: powering vehicles, producing plastics, and serving as the backbone of modern energy systems. Yet, refining raw oil also generates a massive amount of a bright yellow byproduct: elemental sulfur. Every year, refineries around the world produce millions of tons of it.[1] Because the huge demand for sulfur is far smaller than its supply, vast piles of it sit unused, often stacked like golden mountains near oil fields or ports. Storing these heaps costs money, adds environmental risk, and drives up manufacturing expenses. For decades, scientists and engineers have been asking: What if this industrial waste could become a valuable construction material?This idea is not new. During the early 20th century, especially around World War I, sulfur was suddenly in high demand in North America. It was needed for making explosives, rubber, and fertilizers. Production doubled within just a few years, prompting chemists to look for new applications.[2,3] One of the most creative ideas was sulfur concrete: a building material that uses molten sulfur instead of cement as the binder.The idea is theoretically simple: when sulfur is heated above 120%u00b0C, it melts into a golden liquid. If this liquid sulfur is mixed with preheated sand or gravel and then allowed to cool, it solidifies again, forming a hard, concrete-like material. Unlike conventional concrete, this process requires no water and takes only a few hours to set. Early pioneers such as Bacon and Davis [4] in the 1920s explored this concept further, producing the first %u201csulfur mortar%u201d that showed surprising mechanical strength and durability.From the 1950s through the 1980s, research centers in the United States and Canada investigated sulfur-based materials. Scientists discovered that sulfur concrete offered several striking advantages: [5 %u2013 10] %u2022 Water-free production: it conserves fresh water, a crucial benefit for sustainability or extraterrestrial environments;%u2022 Less energy consumption: sulfur melts at around 120%u00b0C, only about one-tenth the temperature required to produce Portland cement, which demands limestone calcination above 1000%u00b0C; [11] %u2022 Fast hardening: as sulfur cools, it simply changes phase from liquid to solid, achieving full strength in less than a day %u2014 no weeks of curing required;%u2022 Excellent corrosion resistance: sulfur is hydrophobic and chemically inert to most acids, making the material ideal for harsh industrial environments.Because of these properties, sulfur concrete found niche uses in chemical plants, wastewater facilities, and marine structures where traditional cement concrete would quickly deteriorate.After a few quiet decades, sulfur concrete is being more used in Western Europe, driven by sustainability goals and carbon-reduction targets. In Belgium, the company Thiomaterials has developed multiple sulfur concrete technologies and begun real-world applications (see Figure 1). In 2021, Belgium%u2019s national railway operator Infrabel installed sulfur concrete railway sleepers along the line between Puurs and Antwerp. These sleepers reportedly cut carbon emissions by 40% compared to cement-based ones and can be fully recycled at the end of their service life. By 2024, long-term tests confirmed their durability even after ten years of simulated use, a strong endorsement for industrial use. Meanwhile, in the Netherlands and France, standardized testing began in 2023 on sulfur concrete sewer pipes produced by A second life of sulfur: sulfur concrete and its chemical and thermal resistanceMixture design for improving the corrosion-resistance of construction materials n Qinjian Wang and Didier Snoeck, BATir Department, Universit%u00e9 Libre de Bruxelles, Bruxelles, Belgium