Influence of E-Coli on workability and strength characteristics of self-consolidating geopolymer concrete based on GGBFS, flyash and alccofine

Abstract

Construction sector across world utilizes cement as one of the most relevant and efficient raw material. It is being estimated that by manufacturing one ton of cement, roughly-one ton of CO 2 gas is emitted into atmosphere. With increasing awareness about global warming, development of alternative binding material that can replace cement completely has gained importance in construction sector. Many studies made on Geopolymer concrete (GPC) has proven its ability to replace cement in construction sector. This experimental investigation concentrates on completely replacing cement by alkali activated GGBFS, Fly ash and alccofine in self-consolidating concrete (SCC) mixes. The current investigation studies effect of E-Coli bacteria on workability and strength characteristics of Self-consolidating geopolymer concrete (SCGC). In this study 10 different SCGC mix samples were prepared by varying cell concentration of E-coli bacteria in order of 0 %, 1 %, 2 %, 3 %, 4 %, 5 %, 6 %, 7 %, 8 % and 9 % of total binder content. Test results indicated that all fresh SCGC mixes with bacteria exhibited better workability with values satisfying EFNARC guidelines. SCGC mix containing E-Coli in cell concentration of 8 % of total binder content gained maximum compressive strength of 36 MPa, flexural strength of 2.4 MPa and split-tensile strength of 2.8 MPa after 28 days of ambient curing. With optical density (OD) values ranging from 0.4 to 0.8, Bacterial survivability (Turbedimetric) test result showed that incorporated bacterial cells remained active within the geopolymer matrix even after 28 days. XRD analysis indicated the formation of quartz, Guanine and Anorthite minerals along with geopolymeric gels indicating a dense microstructure of geopolymer matrix resulting from enhanced geopolymerization process.