Ceramics-Silikáty 54, (4) 325 - 333 (2010)

An experimental study for the resistance of mortar specimens incorporating 0%, 5%, 10%, 15%, 20%, 25% and 30% metakaolin [produced by firing Kaolin at 820 °C for 2 hrs (MK)] to the magnesium chloride solution was reported. Results confirmed that mortar specimens with a high replacement level of metakaolin showed higher resistance to magnesium solution. Due to, the reduction of calcium hydroxide and the increase of secondary C–S–H in the cement matrix due to pozzolanic reaction of metakaolin.Compressive strength values of the blended OPC mortars specimens were improved relative to those contains no MK up to 25 wt.% OPC substitution, and the following decrease up to 30 wt.% MK. SEM microstructures indicate a good improvement for the matrix structure of the blended cement mortars where a more dense structure was observed.