Feasibility Study of Sandy Soil Stabilization with Glass Powder and Natural Pozzolan Based Geopolymer

Improvement of problematic soils using chemical additives has had a long history in the field of geotechnical engineering. One of the common materials used for soil stabilization is Portland cement that has had detrimental impacts on the environment thus engineers are looking for a green material with the same characteristics as an alternative. Geopolymer materials have recently drawn attentions of civil engineers since they have similar properties to cement. In current study, natural pozzolan based geopolymer has been used for improvement of sandy soil. Besides efforts have been made to use glass powder as a replacement for natural pozzolan. Two kinds of alkaline activators were used. The first type was a combination of sodium hydroxide and liquid sodium silicate and the second type had different concentrations of sodium hydroxide. Beside the unconfined compressive strength test which was the main comparison criteria, the microstructural characteristics of geopolymeric samples were investigated with X-ray diffraction (XRD) and scanning electron microscopy (SEM). Results indicated that with the increase of pozzolan and activators, the unconfined compressive strength of the samples were increased. In addition, increasing the concentration of type II activator will lead to the increase of unconfined compressive strength of the samples.