Portland Calcium Sulphoaluminate Cements For Rapid Pavement Repair : Liam Devlin

Portland Calcium Sulphoaluminate Cements for Rapid Pavement Repair

Liam Devlin 1,

1 Chief Scientist, BSC Chem, PERAGRENE 2 Postgraduate supervisor, Visiting Fellow, ARC Training Centre- Chemical Industries, School of Chemistry, Faculty of Science, UNSW, Sydney

ABSTRACT

Belitic Calcium Sulphoaluminate (BCSA) cements have dominated ultra-rapid repair concrete for over 30 years. In Australia BCSA is 100% imported from China or the USA. CSA cements were not approved for use in structural concrete in Europe until an EOTA Assessment was completed in 2017. The Dry Mix Mortar industry has used all types of CSA cements for over 40 years in non-structural applications such as floor levelling and repair mortars. Consequently, the Dry Mix Mortar industry has developed considerable expertise in the chemistry and applications. The status change in Europe has prompted a rapid increase in research in the field, both from academia and global scale cement producers. There is stronger focus today on blending higher actives CSA clinker with Ordinary Portland Cement. This provides lower costs, more local content and better formulation flexibility. Australian scientific knowledge in this field is limited and Peragrene is investing in building local expertise, by sponsorship of a Master’s degree, in house research and Australian Research Council subsidised projects at major universities. This paper briefly reviews the history of CSA cements and discusses some fundamental materials science aspects of blends with Portland Cement. Durability of BCSA in pavements has well established usage history. Blends of CSA with Portland Cement have a shorter history. The paper looks at the key factors determining durability. The research projects on durability are focusing on more local climate conditions such as thermal cycling.