EXPERIMENTAL STUDY ON INFLUENCE OF VARIOUS BACTERIA ON WORKABILITY, STRENGTH AND DURABILITY CHARACTERISTICS OF GEOPOLYMER CONCRETE

Abstract

 Cement is widely used as a crucial raw material in construction across the globe. To meet the demands of the construction industry, significant quantities of cement are produced annually, leading to the release of substantial amounts of CO₂ into the atmosphere. With growing awareness of global warming, geopolymer concrete (GPC), an inorganic polymer binder, was developed as an eco-friendly alternative to ordinary Portland cement (OPC) concrete. Recent research has focused on improving the viscosity and workability of GPC, leading to the development of self-consolidating geopolymer concrete (SCGC). This experimental study examines the effects of three microorganisms—E. coli, Bacillus subtilis, and Bacillus pseudofirmus—on the workability, strength, durability, and microstructural characteristics of SCGC. Four different SCGC mixes were prepared and subjected to various workability, strength, and durability tests, alongside SEM and XRD analyses to study their microstructural development. The results indicated that the SCGC mix containing E. coli bacteria exhibited superior microstructural development, the highest workability with a slump value of 706 mm, and the maximum compressive strength of 44.30 MPa after 28 days of ambient curing. Additionally, the hardened SCGC mix with E. coli showed enhanced resistance to acid and alkali attacks and minimal water absorption.