Effect of Metakaolin and Lime addition on Geopolymerization of Construction and Demolition Waste

Abstract

Abstract New challenges are arising everyday due to the waste management problems. Construction is one of the most important activities and it is seen as a real threat to sustainable development considering permanent use of limited natural resources and the disposal of huge amount of debris. Construction and demolition wastes contain aluminosilicates as major constituents. In this study an attempt has been made to investigate the mechanical effect of the addition of metakaolin and lime to synthesize geopolymer using construction waste. The compressive strengths of the geopolymer products developed at 28 days from brick dust, metakaolin and lime with activator solution were found 8.35, 21.30 and 25.0 MPa, respectively. Addition of metakaolin and lime had increased the compressive strength by more than 2.5 and 3.0 folds respectively in comparison to the product obtained from brick dust only. The FTIR spectra and SEM-EDX micrographs of the reaction had shown structural changes and formation of aluminosilicate hydrate and calcium silicate hydrate gel. Geopolymer synthesized from brick dust was found very hard ceramic like product with potential applications such as pavement blocks, tiles, retaining walls etc.