Experimental evaluation on workability and strength characteristics of self-consolidating geopolymer concrete based on GGBFS, flyash and alccofine

Abstract

Increase in cement production due to growing construction sector across the world has resulted in emission of disastrous amount of CO2 gas into atmosphere. This has led to the invention of.an inorganic polymer binder termed as geopolymer concrete (GPC). Studies focusing on developing self-consolidating ability in GPC have gained importance in recent times. Such concrete is termed as Self-consolidating geopolymer concrete (SCGC). This experimental investigation studies the workability and strength characteristics of SCGC based on GGBFS, Fly ash and Alccofine. Laboratory tests were conducted on 6 different SCGC mix design samples. For all mixes binder content was varied in order of 400 kg/m3 and 450 kg/m3. Molarity of NaOH solution was also varied for each mix in order of 10 M, 12 M and 14 M. 60% GGBFS, 35% low calcium fly ash and 5% alccofine were used in all mixes to produce SCGC. Workability of SCGC was determined by conducting J-ring test, Slump test, L-Box test, T50 slump test and V-funnel test as per the guidelines established by EFNARC. Strength characteristics of SCGC were determined after 7 and 28 days by conducting flexure test, compression test and split-tensile test. SEM and XRD analysis were used to determine micro-structure and chemical composition of SCGC respectively. Test results indicated that the SCGC mix containing 14 M NaOH solution and 450 kg/m3 binder content exhibited better workability characteristics with a slump flow of 673 mm and strength characteristics with a maximum compressive strength of 40.2 MPa after 28 days. Maximum workability with a slump flow of 715 mm was exhibited by SCGC mix containing 10 M NaOH solution and 450 kg/m3 binder content. Reference mix containing 100% GGBFS, 500 kg/m3 binder content and 16 M NaOH solution achieved highest compressive strength of 43.5 MPa, flexural strength of 2.9 MPa and tensile strength of 3.5 MPa after 28 days. SEM analysis indicated that the SCGC mix containing 14 M NaOH solution and 450 kg/m3 binder content developed better micro-structure.