A mix design procedure for geopolymer concrete with fly ash

Effective promotion of GPC is required in order to minimize the environment threat due to fly ash waste disposal and reduce cement consumption. To achieve this, specific mix design procedure for development of GPC is essential. Therefore, efforts have been made in this paper to develop a mix design methodology for GPC with the main focus on achieving better compressive strength in an economical way for different alkaline solutions to binder proportions. Low calcium fly ash brought from local sources as the binder material, sodium hydroxide and sodium silicate as alkaline activator solutions, and aggregate grading based on DIN standards, have been employed for conducting experimental investigation. Correlation between the alkaline activator solution to binder ratios and 28 day compressive strength has been investigated to propose conceptual mix design method for GPC in a rational way. Mix design is proposed for various AAS/FA ratios ranging from 0.4 to 0.8, and the 28 day compressive strength as high as 54 MPa has been noticed. The design methodology proposed has been given step-wise and the same has been verified with the help of an example in this paper. (C) 2016 Elsevier Ltd. All rights reserved.