HIGH CALCIUM FLY ASH GEOPOLYMER CONTAINING NATURAL RUBBER LATEX AS ADDITIVE

This research studied the use of natural rubber latex as an additive in high calcium fly ash geopolymer. The high calcium fly ash geopolymer with natural rubber latex (medium ammonia concentrated latex type) content of 0, 1, 2, 3, 5 and 10 percent by weight of fly ash was incorporated in the mixtures. In this study, geopolymer mortars were prepared. The ratios of sand to fly ash of 2.75, liquid to fly ash ratio of 0.6 and Na2SiO3 to NaOH ratio of 0.33 were used for all mixtures. Setting time, workability, absorption, apparent porosity, compressive strength, flexural strength, and surface abrasion resistance were tested. The test resulted shows that the optimum natural rubber latex content was 1.0 percent by weight of fly ash to obtain geopolymer mortar with improved mechanical properties and a slight reduction in workability, and an increase in setting time. The addition of more than 1 percent by weight of fly ash latex started to reduce the compressive strength due to increases in rubber particle, interface, and gap between rubber particle and paste.