The effect of natural pozzolan on delayed ettringite formation of the heat-cured mortars

摘要

Delayed Ettringite Formation (DEF) is an internal sulfate attack caused by early age heating to a temperature of over 70 ℃. In this paper, the effect of natural Algerian pozzolan on the expansion of cement mortars caused by DEF was investigated. For this purpose, a portion of cement was replaced by natural pozzolan, with three different dosages (10%, 20% and 30%) and finenesses (fine, medium, and coarse). The results obtained highlighted the significant effects of natural pozzolan on DEF and the correlation existing between the expansion of the heat-cured mortars and the evolution of their mechanical properties.