Improvement of Tabriz Green Marl Using Alkaline Activated Zeolite and Metaclay

Marl or marl clays are named for carbonated soils with the amount of carbonate in varying proportions from 20 to 55% (Elert et al., 2017). Marls are one of the most important problematic soils that not only the problem of volume changes but also their bearing capacity is lower than coarse-grained beds, so not meet the load-bearing goals of engineering structures. Different improvement methods are proposed to improve the engineering characteristics of problematic soils, the most common is using of lime for this purpose in clayey soils (Al-Mukhtar et al., 2012 and Obuzor et al., 2012) But this substance is less effective in marls (Ghobadi et al., 2014 and Ureña et al., 2015). According to the history of soil modification, the geopolymerization method can be introduced as the third generation of cementation methods after lime and cement (Li et al., 2010). Geopolymers are alkaline activated bonds with low calcium and medium to high aluminum produced by the reaction between alkaline hydroxide solution and materials containing alumina silicate (Provis et al., 2009 and Yung-Ming et al., 2016).The purpose of this research is using the geopolymerization technique to stabilize Tabriz carbonate clay with the approach of controlling deformations and increasing strength. To achieve this outcome, laboratory studies have been carried out on Tabriz green marl with alkali activated zeolite and metaclay as sources of alumina silicate to form cemented bonds. The alkali activator used in this study is sodium hydroxide with different concentrations to achieve optimal results. For this purpose, multiple tests of uniaxial compressive strength have been used to evaluate the strength of stabilized soil. The effective parameters studied in the current research can be referred to the weight percentages of materials containing alumina silicate (zeolite and metaclay), curing time and molarity of the alkaline solution (NaOH).