Advances in understanding ye'elimite-rich cements

In this review, we discuss the recent advances in understanding ye'elimite-rich cements. These cements can be classified as follows: (1) Low belite ones namely called calcium sulphoaluminate cements (CSA) where the main use is in special applications or when combined with OPC and calcium sulphate sources in structural application (2) High belite ones namely Belite Ye'elimite ferrite cement (BYF) where their development as an alternative low carbon binders is aimed to replace Portland clinker in structural applications. The main hydrating phase at early age in both systems is ye'elimite. Its formation, its reactivity and its extent of reaction and space filling when hydrating define the properties of the cement. Recent advances in understanding these properties are critically analyzed. Recent activities on the clinker formation and production at laboratory and industrial scale are reported. Additionally, the effects of aluminate-rich minerals are reviewed in detail, with a focus on their influence on the hydration mechanism and the resulting hydrates assemblage and their stability in ye'elimite rich systems. Applicability of thermodynamic calculation and its limitations are discussed to underline the role of the chemical environment at each reaction step on the hydrates assemblage.