MODELING OF COMPRESSIVE STRENGTH OF METAKAOLIN BASED GEOPOLYMERS BY THE USE OF ARTIFICIAL NEURAL NETWORK

In order to study the effect of R2O/Al2O3 (where R=Na or K), SiO2/Al2O3, Na2O/K2O andH2O/R2O molar ratios on the compressive strength (CS) of Metakaolin base geopolymers, more thanforty data were gathered from literature. To increase the number of data, some experiments were alsodesigned. The resulted data were utilized to train and test the three layer artificial neural network(ANN). Bayesian regularization method and Early Stopping methods with back propagationalgorithm were applied as training algorithm. Good validation for CS was resulted due to theinhibition of overfitting problems with the applied training algorithm. The results showed thatoptimized condition of SiO2/Al2O3, R2O/Al2O3, Na2O/K2O and H2O/R2O ratios to achieve high CSshould be 3.6-3.8, 1.0-1.2, 0.6-1 and 10-11, respectively. These results are in agreement with probablemechanism of geopolymerization.