MIX DESIGN OPTIMIZATION AND EARLY STRENGTH PREDICTION FOR AMBIENT-CURED GEOPOLYMER CONCRETE PAVEMENTS

Abstract

To lower the emission of carbon from concrete construction and production and encounter sustainability standards and constraints, a new and workable binding material is required to replace Ordinary Portland Cement. The geopolymer is generally made from alumino-silicate powder activated by high activating alkali solution like sodium silicate or NaOH solution. The geopolymer concrete formed from powdered activated alkali activators on blending with the source material is proved to show the similar mechanical and physical traits of OPC. The study has shown that geopolymer concrete having the full replacement of OPC by Ground Granulated Blast Furnace Slag and Fly Ash achieved a compressive strength of 20-40 MPa at 7 days irrespective of the need for heat curing of the sample or specimens while it achieved a tensile strength of 3-6 MPa making it a sustainable choice for design of rigid pavement. This study used two types of activating solution for geopolymer binders with varied amounts of fly ash and slag. At ambient curing conditions, the engineering properties of geopolymer concrete of four different mix proportions of FA and GGBFS along with varying molarity of NaOH were examined in detail with their strength values and microstructural studies. With these results, strength prediction model is generated.