Artificial coarse aggregate from waste materials, fly ash and Msand dust through geopolymerization

Abstract

Coarse aggregate is considered the most vital aspect, providing quantity and strength to the concrete. The aggregates are obtained mainly from natural resources by quarrying rocks or riverbeds. Each year, construction industries use large amounts of natural aggregates, resulting in the depletion of raw materials. Different methods, such as sintering, cold bombing, autoclaving, and geopolymerization, can prepare artificial coarse aggregates. Geopolymerization is a chemical reaction between an alkali solution and source materials containing alumina and silicate. The main objective of this study is to develop artificial aggregates with M sand dust and fly ash by geo polymerization. The ratio of Fly ash to M Sand Dust adopted is 40:60 by weight. Different molarities of sodium hydroxide was used for making the artificial aggregates with a solution-to-binder (S/B) ratio of 3.5 and a sodium silicate-to-sodium hydroxide ratio of 2.5. The mechanical properties of the developed lightweight aggregate are determined as per the specification requirement in IS 9142 (1979) for artificial lightweight aggregates for concrete masonry units. By comparison, these geopolymer aggregates are sustainable, and aggregates with 12 molarity NaOH showed better properties than other molarity NaOH aggregates based on its mechanical properties.