Experimental evaluation of sustainable geopolymer mortars developed from loam natural soil

Abstract

Natural soil can play an important role in the production of geopolymer due to having required aluminosilicate precursors and abundant availability. Numerous aluminosilicate materials have been used in the past for the production of geopolymers but they have some limitations like various ashes can be toxic during handling and processing due to presence of harmful components. The major purpose of this study was to develop geopolymers via cheap and easily available aluminosilicate material like loam type of natural soil. Geopolymer specimens were prepared by mixing natural soil and other required precursors such as sodium silicate and sodium hydroxide through ball milling. After the preparation of mortars via subsequent hydrothermal treatment for 24 hours at 60⁰C, the physical and mechanical properties were evaluated. FTIR analysis showed that geopolymerization reaction occurred in soil-based geopolymer mortars. This was confirmed by detecting some zeolitic phases like Albite/Anorthite in geopolymers. X-ray diffraction analysis also confirmed the presence of these zeolitic phases. The maximum compression strength of 22.70 MPa was achieved for A-75 composition which proved to be an optimum composition in this study which is somehow comparable to the compressive strength of ordinary Portland cement (OPC) mortars.

Keywords

• soil
• geopolymers
• mortars
• sustainable building materials
• ordinary portland cement