Research on the Possibilities of Using Sulfur Concrete for Road Infrastructure Construction—Assessment Based on European Standards

Sulphur is generated in large quantities as an industrial byproduct, and one promising method of its reuse is in sulphur concrete as an alternative binder to Portland cement. In this study, a sulphur polymer (waste sulphur) modified with 5% styrene was evaluated as a binder in concrete for road infrastructure. The sulphur concrete was tested for its compressive strength, abrasion resistance, water absorption, freeze–thaw durability, water impermeability, and leachate chemistry, in relation to relevant European standards for transport concretes. The modified sulphur concrete achieved high early strength (compressive strength class C40/45) and exhibited very low water absorption and high resistance to abrasion and water penetration. However, it did not satisfy frost resistance requirements: after 150 freeze–thaw cycles, its compressive strength dropped by over 30% (well beyond the 20% acceptable loss), meaning that the material only achieved an F50 rating instead of the F150 rating that is required. In addition, the material is inherently flammable, which poses safety limitations. Unmodified (styrene-modified only) sulphur concrete cannot yet replace conventional concrete in structural applications where it would be exposed to significant freeze–thaw cycling or high fire risk. It may be suitable for less demanding uses, for example in chemically aggressive environments or for precast elements that are not subject to freezing. Further research should explore modifications (such as fibre reinforcement or additional polymer additives) to improve the frost resistance and overall durability of sulphur concrete for broader infrastructure applications.