Mechanical and durability properties of alkali-activated binders based paver blocks derived from secondary sources

Abstract

In this research study, low calcium fly ash (FA) and Ground granulated blast furnace slag (GGBS) are used as precursors activated with the solution of sodium hydroxides (SH) and sodium silicates (SS) for the development of geopolymer(GP) paver blocks. A total of 12 FA-GGBS based GP concrete mixes are developed by varying the ratio of SS solution to SH solution (0.25,0.67 and 2.33) along with the binder variation of FA: GGBS (80:20,70:30,60:40 and 50:50) under ambient curing conditions. From the synthesised FA: GGBS and alkalinity ratio, the required GP mixes for paver blocks suitable for medium traffic (M40) and heavy traffic (M50) conditions are formulated. The properties of the GP paver blocks such as mechanical and durability properties are evaluated as per the codal recommendations. All the GP paver blocks satisfy the minimum breaking load criteria with respect to flexural strength and split tensile strength and fall within the allowable abrasion resisting limits. The research findings affirm that the FA-GGBS blend GP paver blocks perform well as per specification requirements. Hence, these GP paver blocks can be adopted for various pavement applications thereby contributing to the adoption of sustainable construction practices.