Calcium Sulphoaluminate-Based Binders to Produce Expansive Concrete for Slabs on Ground

This article is aimed to the study of the influence of water/binder ratio, set retarding admixture dosage and curing condition on the properties of low environmental impact expansive concretes manufactured with calcium sulphoaluminate cement (CSA), gypsum, lime and supplementary cementitious materials instead of Portland cement (OPC). Experimental results indicated that tartaric acid-based set-retarding admixture influences the behaviour of concrete both in fresh and hardened state. In addition, according to Abram's model, results evidenced the water/binder ratio as a key factor in strength gain. Moreover, tartaric acid allows the production of shrinkage-compensating Portland-free concretes recommended for slabs on ground. Finally, by replacing OPC with CSA-based binders, it is possible to obtain, both for CO2-emissions and energy consumption, a reduction up to 60% at equal strength class respect to an OPC-based concrete.