Effect of superplasticizer types and dosage on the flow characteristics of GGBFS based self-compacting geopolymer concrete

Abstract

Self-compacting geopolymer concrete (SCGC) is produced from waste materials that act as binders or precursors promoting sustainable concrete. Among all components of the SCGC mix, the superplasticizer dosage primarily controls the workability of concrete along with mechanical strength. An attempt is made in this current study to find the best suitable type of superplasticizer and its dosage through given fresh property investigation. For the accomplishment of the project objective, four types of superplasticizers are considered in the SCGC mix preparation and are polycarboxylate ether-based, modified naphthalene-based, lignosulphonate-based, and mother liquor-type superplasticizers. The superplasticizer dosage considered in each is 4%, 6%, and 8%. In the absence of a suitable design standard SCGC mix designs are prepared and concrete is produced with characterized material components. Twelve M25 SCGC mix designs are prepared with some constant parameters like 12 M concentration of sodium hydroxide, the ratio of sodium silicate to sodium hydroxide as 2.5, and 24% extra water addition. The freshly prepared concrete has undergone various workability tests to examine the filling ability (FA) (slump flow, T50cm slump flow, V-funnel); passing ability (PA) (L-box, J-ring); and segregation resistance (SR) (V-funnel at T5minutes). The 6% naphtha (NP)-based superplasticizer is regarded as the superior superplasticizer from the fresh property consideration in the GGBFS-based SCGC.