INVESTIGATING SHRINKAGE CHANGES OF NATURAL POZZOLAN BASED GEOPOLYMER CEMENTPASTE

Shrinkage behavior of a geopolymer cement paste prepared from pumice-type natural pozzolan was studiedby changing parameters of chemical composition including SiO۲/Na۲O molar ratio of activator and total molar ratiosof Na۲O/Al۲O۳, and H۲O/Al۲O۳. For investigating the effect of curing conditions on shrinkage, hydrothermal curingwas also applied. The obtained results clearly revealed the governing effect of chemical composition on shrinkage.Mixes with different Na۲O/Al۲O۳ molar ratios exhibited different shrinkage behavior due to variations made inSiO۲/Na۲O molar ratio. Application of hydrothermal curing after a ۷-day period of precuring in humid atmospherealso showed strong effect on shrinkage reduction.

کلیدواژه ها:

Geopolymer cement ، Shrinkage ، Chemical Composition ، Curing ، Natural Pozzolan