Alite-belite-ye'elimite cements: Effect of dopants on the clinker phase composition and properties

Clinkers with alite-belite-ye'elimite (ABY) are considered as eco-friendly cements. Clinkering (2 Kg) of two types of ABY clinkers was optimized: standard-ABY, with CaF2 and ZnO as dopants (32.6 wt% alite, 30.4 wt% β-C2S and 15.6 wt% ye'elimite) and αABY, with CaF2, ZnO, B2O3, Na2O (14.4 wt% alite, 37.1 wt% β-C2S, 18.5 wt% α′H-C2S and 7.5 wt% ye'elimite). Zn and F were mainly incorporated in alite and ferrite as dopants determined by EDS semi-quantitative analysis. The effect of dopants on the hydration of the cement mortars has been tested. Thus, standard-ABY develops 29.9 MPa compressive strengths at 1 day while αABY does 16.8 MPa, mainly due to the higher amount of alite of the former. The presence of α′H-C2S in αABY increases mechanical strengths at 28 days of hydration from 44.7 MPa of standard-ABY to 74.9 MPa.