Performance of Sulpho-Based Rapid-Hardening Concrete

摘要

Calcium sulphoaluminate cements (CSA) may provide an eco-friendly alternative to ordinary portland cement (OPC). These cements have been widely used in the past, alone or in combination with OPC, because of their well-known rapid hardening and shrinkage-compensating behavior. CSA cements are characterized by a lower environmental impact than OPC, thanks to a different raw material mixture and a lower energy demand associated to the production process. In this study, the mechanical and the durability characteristics have been investigated, according to the European standards, both for CSA-OPC blends and pure CSA containing concretes. Tests have been carried out using different OPC sources and blending percentages, starting from a 85/15 OPC/CSA blend to a 100% CSA cement. The concretes performances have been compared to reference concretes made with only OPC, the tests included slump retention, compressive strength, drying shrinkage, resistance to freezing and thawing and resistance to chloride penetration. A satisfactory behavior has been observed, especially for the 70/30 OPC/CSA blend, which showed good performances in all the tests.