An experimental study on the development of self-compacting alkali-activated slag concrete mixes under ambient curing

Abstract

This study was carried out to develop alkali-activated blast furnace slag concrete having self-compacting properties under ambient curing. Ground Granulated Blast Furnace Slag was used as the binder, and the blended sodium silicate liquid and sodium hydroxide pellets were added to activate the GGBFS. Fine aggregate and coarse aggregate were replaced by unprocessed blast furnace slag and electric arc furnace slag. There were a huge number of parameters, such as binder content, water-binder ratio (w/b), Na2O% and activator modulus (Ms), that influence the fresh and hardened properties of self-compacting alkali-activated Slag concrete. Taguchi’s Design of Experiments (DOE) method was used to minimize the possible number of mixes to perform experiments. Taguchi’s DOE method uses a specific design based on the orthogonal arrays to understand the entire parametric space with a less number of possible experiments. Therefore, based on Taguchi’s DOE method, detailed experiments were carried out corresponding to only nine mixes known as calibration mixes. Mix-7 shows higher compressive strength (at 28 days), modulus of elasticity, split tensile and flexural strength are 46.2 M of 46.2 MPa, 30.27 GPa, 4.43 MPa and 5.31 MPa, respectively. The results of this study show that the 28 days mechanical strength of SCAASC mixes is most controlled by Na2O% followed by binder content (GGBFS), Ms value and w/b ratio.