INVESTIGATING SHRINKAGE CHANGES OF NATURAL POZZOLAN BASED GEOPOLYMER CEMENTPASTE

Shrinkage behavior of a geopolymer cement paste prepared from pumice-type natural pozzolan was studied by changing parameters of chemical composition including SiO2/Na2O molar ratio of activator and total molar ratios of Na2O/Al2O3, and H2O/Al2O3. For investigating the effect of curing conditions on shrinkage, hydrothermal curing was also applied. The obtained results clearly revealed the governing effect of chemical composition on shrinkage.Mixes with different Na2O/Al2O3 molar ratios exhibited different shrinkage behavior due to variations made in SiO2/Na2O molar ratio. Application of hydrothermal curing after a 7-day period of precuring in humid atmosphere also showed strong effect on shrinkage reduction.