Modification of consolidation parameters of marl soils using geopolymerization mechanism (case study: Tabriz marl)

The process of forming cemented alumino-silicate bonds in the presence of an alkali activator is referred to geopolymerization. In this study, the application of this method has been evaluated to modify the consolidation coefficients of Tabriz marl. For this purpose, zeolite and metaclay were used separately as the sources of alumina-silicate and sodium hydroxide solution as an alkali activator. The effect of marl type, weight percentage of zeolite and metaclay, alkali activator concentration and curing time has been examined on consolidation behavior of improved samples. The results indicate very appropriate effect of geopolymerization on consolidation characteristics of marl and the optimal composition for the samples has been obtained. In the optimal samples of zeolite geopolymer with yellow or green marl (15% zeolite and 12 M alkaline solution), the coefficients of Cc and Cs are improved by about 70% to 80% and this reduction is less in the optimal samples of metaclay geopolymer. By comparing all of results, it can be concluded that zeolite is more suitable source of alumina-silicate for the purpose of this research, and on the other hand, the amount of modification of consolidation coefficients of yellow marl geopolymer samples is more than similar samples containing green marl.