Consolidation of soft clay mixed with fly ash geopolymer

Abstract

This paper investigated consolidation of soft clay mixed with fly ash geopolymer. Soft clay was collected at a depth of 5-8 m, Klong Toey, Bangkok. The dominant factors used in this study were the moisture content of soft clay (W_n) of 1LL, 2LL and 3LL (LL = liquid limit) and soft clay:fly ash (SC:FA) ratios of 90:10, 70:30 and 50:50. Whereas, liquid alkaline:fly ash ratio of 0.6, sodium silicate:sodium hydroxide ratio (Na₂SiO₃/NaOH) of 1, NaOH concentration of 8 molar were fixed. The tested result showed that the moisture content of soft clay (W_n) and soft clay:fly ash (SC:FA) ratios have an effect on settlement of soft clay mixed with fly ash geopolymer. The settlement of soft clay mixed with fly ash geopolymer increased as W_n content increased because the increase in void content resulting from the increase in water. However, the settlement of soft clay mixed with fly ash geopolymer decreased with increase in FA content. This is because liquid alkaline can leach Si and Al from FA to react with Ca which result in pozzolan reaction.