Promulgation of engineering and sustainable performances of self-compacting geopolymer concrete

Abstract

This study proposes a user- and eco-friendly methodology to optimize the mix proportion of superplasticizer-free self-compacting alkali-activated concrete (SCAAC). This methodology allows tailoring SCAAC for a desired water-binder ratio, alkaline activator content, and ratio to realize a targeted compressive strength and sustainability index. The validity of the proposed methodology was established via a series of physical tests and ANOVA analyses. The findings indicate that the attained flow properties of the developed SCAAC have significantly improved, i.e., from 490 to 705 mm for mixes of water/binder ratio of 0.45–0.65. The compressive strength results indicates that the water/binder ratio of 0.45 possess 46 MPa at the curing age of 28-d, whereas the water/binder ratio of 0.65 possess a 28-d strength of 39 MPa. The present work proposes the guidelines for the production of SCAAC, since there is no guidelines or standards for SCAAC. To showcase the proposed methodology, this study concludes with a step-by-step procedure for arriving at an optimized design mix for a superplasticizer-free Fly Ash Ground Granulated Blast Furnace Slag (FA-GGBS) based SCAAC. Furthermore, sustainability index (Cost, Carbon and Energy efficiency) analysis was performed for the SCAAC mixes with and without SP. From the analysis it is found that an increase in the SP dosage from 1 to 6% increases the cost of the production of the mix. Also, it increases the energy demand for its production and liberates huge amount of carbon dioxide in the open atmosphere.