Mechanical performance comparison between sulfo-based and portland concretes

Calcium-sulfoaluminate cement (CSA) represents an eco-friendly alternative to portland cement (PC), thanks to its lower energy consumption due to different production process and raw materials, featured by high early ages resistance and increased volume stability deriving from the massive ettringite production as the main ye'elimite hydration product. Among the new possibilities opened by such a cement, one of the most promising seems to be the use of it in blended systems with PC in binder, mortar and concrete form, for both structural and non-structural uses. In this sense, the definition of the constitutive laws for these new systems, which are based on different chemistry compared to portland cement, is fundamental for the structural engineer. This paper presents a mechanical performance comparison between pure CSA, PC and blends of the two binders at the PC/CSA ratio from 70/30 to 50/50 in terms of compressive, flexural and splitting tensile strength, elastic and dynamic modulus of elasticity and stress-strain diagrams in compression. The experimental data were considered as input for a comparison between the materials in terms of constitutive relations proposed by the main technical documents and standards: the results show that CSA is basically compliant with the present models, both for pure and blended mixtures.