STRENGTH DEVELOPMENT AND DRYING SHRINKAGE OF ALKALI ACTIVATED METAKAOLIN-PORTLAND CEMENT MIXES

The strength development (up to 28 days) and drying shrinkage of alkali-activated metakaolin-Portland cement mortars at room temperature curing using an Na₂SiO₃ to NaOH ratio of 1.5 were investigated. The effects of different Portland cement (0-30%) and metakaolin (70-100%) mixes are reported on. The setting time and drying shrinkage were found to be reduced with increasing Portland cement contents when both materials were used. The early strength at 3 days was higher for the 100MK mix, but higher strength developments between 3 and 7 days were found in PC-MK mixes. At 28 days, the highest compressive strength was found in the mixes with a metakaolin content between 80-85%. The TGA analysis results showed that the N-A-S-H/(N, C)-A-S-H phases were detected as a geopolymer product.