Properties of flyash-dolomite powder-mangalore tile waste powder based alkali-activated binder cured in ambient condition

Abstract

This research addresses the slower reaction rate of flyash based alkali activated binders by investigating the use of dolomite powder (DP) and Mangalore Tile waste powder (MTWP) to enhance the reaction rate and improve binder properties. The study evaluates the feasibility of combining these materials with flyash to develop effective alkali activated binders. Material characterization was performed to access their suitability as precursors in alkali activation. The proportions of these precursors were varied while maintaining a constant rate of alkali activators such as sodium hydroxide and sodium silicate. Tests for initial and final setting times, flowabilty, pH, electrical conductivity and compressive strength of the binders were conducted. Microanalysis supported the findings by providing detailed insights. Results indicate that the alkali activated FA-DP-MTWP binder exhibited faster setting and hardening with decreased flow ability. The pH of all FDT binder mixes provides necessary alkaline environment for forming stable reaction products like CSH, CASH, NASH and MSH, as identified by SEM, EDS, and XRD studies. This higher level of these activation products also lead to increased electrical conductivity. Optimal precursor utilization was achieved with 5% MTWP and 10% DP in the total binder, beyond which DP and MTWP acted only as fillers. Mechanical, mineralogical, and morphological analyses confirmed the binder's satisfactory performance and cementitious properties, demonstrating its potential value for construction applications. The study concludes that incorporating these materials can effectively enhance the properties of flyash based alkali activated binders. Graphical abstract