Investigation of Groundnut Shell Powder on Development of Lightweight Metakaolin Based Geopolymer Composite: Mechanical and Microstructural Properties

The aim of the present project deals with the use of the available agricultural by-product groundnut shell ash (GSA) as replacement (0, 10, 20 and 30 wt.%) to metakaolin for the synthesis of lightweight geopolymer. Two alkaline solutions (8 and 10M) have been used as activator solution. The resulting product was characterized using XRD, FT-IR, SEM-EDS analyses as well as physico-mechanical properties. The results revealed that the addition of the GSA literally decreased the compressive strength from 21 to 14 MPa (8M) and 30 to 15 MPa (10M). Bulk density was ranged between 1.21 and 1.10 g.cm − 3 and 1.51–1.20 g.cm − 3 . Increasing of the groundnut shell ash content up to 30 wt.% leads to the high porosity (38.13 and 40% vol). SEM images revealed that the microstructure of reference geopolymer (MKGA0) appeared denser than those containing additive (MKGA20) justifying the deterioration in the mechanical strength. The end-products appeared as promising candidate for non-structural application in construction.