Performance Evaluation of Geopolymer Mortar Mixes Using Recycled Fine Aggregate

Abstract

Manufacturing of Ordinary Portland cement (OPC) requires huge quantity of natural resources, energy and it releases large amount of carbon-dioxide to the environment. Numerous research efforts have been made continuously to establish geopolymer as the most suitable alternative binder material in view of economical and environment consideration. With the rapid growth in construction activities, high amount of construction and demolition waste (C&DW) is generated and large volumes of natural resources are also being consumed by the construction industry. As a result, both the quantities of C&DW to be disposed off and the scarcity of natural resources are increasing day by day. To promote sustainability in construction industry, the use of recycled concrete aggregates, resourced from C&DW is very important and provides a useful solution for the production of concrete. Here an attempt is made to use C&DW as recycled fine aggregate (RFA) for the production of fly ash based geopolymer mortar mixes. Effects of the concentration of sodium hydroxide solution, the ratio of sodium silicate solution to sodium hydroxide solution, the ratio of alkaline liquid to binder, different curing regimes and RFA content on the properties of mortar mixes produced have been explained based on the observations at laboratory. Experimental results indicate that 20% RFA can be used effectively to obtain better performances of the mixes. Using the observed results in the laboratories, prediction models for water absorption capacity, compressive strength and drying shrinkage of the produced geopolymer mortar mixes were developed using artificial neural networks.