UTILIZATION OF GEOPOLYMER ON IMPROVEMENT OF LOESS SOIL USING PALM OIL FUEL ASH AND GRANULATED BLAST FURNACE SLAG

Abstract

This research was aimed to improve the loess soil for base course using palm oil fuel ash and granulated blast furnace slag – based geopolymer and compared to the conventional soil cement.  The unconfined compression test and wet-dry durability test were performed in laboratory. The ratio cement is 5, 7, 9, and 11 percent by mass with the room temperature curing for 2, 7, and 28 days. Soil geopolymer used palm oil fuel ash of 5 and 10 percent by mass and 5 percent of palm oil fuel ash mixed with 3 percent granulated blast furnace slag by mass. The concentration of sodium hydroxide solution of 10 molars with the ratio of sodium silicate and sodium hydroxide of 1:3 was used as alkali base. The determined curing phase was 2, 7, and 28 days, controlling temperature at 70, 90, and 110 degrees of Celsius at the first day.  The results shown that the soil geopolymer using palm oil fuel ash mix granulated blast furnace slag 5 with 3 percent by mass provided higher strength than using palm oil fuel ash 5 percent by mass about 2.8 percent at 70 degrees of Celsius at curing 28 days, and by exhibited higher strength than soil cement used 5 percent about 11.7 percent.  In the term of percent weight loss on durability test, geopolymer using palm oil fuel ash with granulated blast furnace slag provided just littlebit more than using palm oil fuel ash as 0.3 percent and less than soil cement used 5 percent is 3.1 percent.