Experimental Investigation of the Mechanical Properties of Blended Concrete Incorporating Metakaolin, Fly Ash, And Rice Husk Ash as Partial Cement Replacements: A Strategy for Sustainable Technology

Abstract

Introduction: Concrete is a crucial and extensively utilized material in the construction industry. The utilization of SCMs has garnered significant interest due to their capacity to tackle sustainability and environmental issues.

Objectives: The purpose of this work is to provide a description of an experimental study that was carried out in order to analyse the mechanical properties of binder concrete that was produced using a mixture of three distinct blending materials for M25 grade and a composition of 0.45 water to binder.

Methods: There were a total of 39 combinations that were produced, and each of them contained varying amounts of Metakaolin (6%, 7%, and 8%), Fly Ash (5%, 10%, and 15%), and Rice Husk Ash (5%, 10%, 15%, and 20%).

Results: The workability of ternary blended concrete mixes fluctuates based on the proportion of Rice Husk Ash, which ranges from 5% to 20%. The control mix attained a maximum slump of 188 mm; however, the slump continually diminishes with increasing percentage replacement. The slump achieved for the optimal replacement percentage was 108 mm, which was satisfactory and somewhat beyond the necessary range. The maximum blending level of 28 percent (8% MK, 10% FA, and 10% RHA) yielded ideal strength parameter values. The compressive strength values recorded after 7, 28, and 56 days of replacement were 30.8 MPa, 38.9 MPa, and 42.6 MPa, respectively. The flexural strength was measured at 15 MPa, whereas the split tensile strength was recorded at 2.5 MPa.

Conclusions: The test results demonstrated a significant improvement in the mechanical properties of blended concrete relative to the control mix.