Long-Term Mechanical Properties of Steel Fiber Reinforced Concrete Under Sulfuric Acid Attack

Abstract

Steel fiber reinforced concrete (SFRC) has significant advantages for preparing pipes, however, concrete sewer pipes are susceptible to deterioration by biological acids (sulfuric acid). In this study, the mechanical properties of SFRC exposed to a sulfuric acid environment for 36 months were monitored, including cubic compressive strength, axial compressive and flexural properties, and so on. Results indicated that the SFRC did not deteriorate after 12 months and instead showed good mechanical properties. The cubic compressive strength was slightly lower than the un-corrosion value (0 months) after 36 months, while the axial compressive and flexural load capacities of specimens were higher than the un-corrosion values. It was also found that the axial and flexural toughness of the specimens after 36 months was higher than that without corrosion. Besides, The thickness of the damage and transition layers increased rapidly after 12 months, reaching approximately 2 mm and 8 mm, respectively, after 36 months. Gypsum was the predominant corrosion product and was observed after 12 months by X-ray diffractometer (XRD) analysis. This study provides valuable evidence for the potential application of SFRC in sewage environments.

Keywords: steel fiber reinforced concrete (SFRC), wastewater environment, sulfuric acid, mechanical properties, X-ray diffractometer (XRD) analysis