Effect of Slag, Natural Pozzolana and Metakaolin on Mortar Properties

The objective of this study is to examine the effect of substitution of cement by three different mineral additions, on the mortar rheological and mechanical properties. This experimentation, considers the fineness of mineral additives with a constant workability. Ordinary Portland Cement was partially replaced by different percentages of slag, pozzolana and metakaolin of 10, 20 and 30%. The obtained results indicate that the resistance of the slags is low at young age. This resistance increases with the age and in function of the fineness. The using natural pozzolana provides a compressive strength comparable to that of the reference mortar at young age, which decreases over the time. The metakaolin requires a large quantity of water to achieve a suitable workability. The compressive strength is substantially greater than the reference mortar at all ages. The results obtained confirmed the great interest in the use of slag and metakaolin additions.