Power Grant - SERB
Project title: OPTIMIZATION AND LIFE CYCLE ASSESSMENT OF THE ONE PART ALKALI ACTIVATOR SOLUTION FOR THE PRODUCTION OF GEOPOLYMER COMPOSITES
Funded by Science and Engineering Research Board.
Amount: Rs 26,76,025/-
Duration: 2022-2025
Principal Investigators: Dr Sivasakthi M
Project summary:
Geopolymer well-known as the alternative binder material as a replacement for of ordinary Portland Cement (OPC) with many advantages like lower CO2 emission, low embodied energy and high early strength etc., The preparation of the geopolymer composite involves solid alumino silicate sources and liquid alkali silicate solution. The concentration alkali silicate solution is corrosive and storage, transport and handling is difficult. The preparation of sodium solution done one day before casting which involves the three solutions namely NaOH lye, sodium silicate solution and water. At first NaOH lye and water has to be missed in appropriate proportion it evolves heat due to the exothermic reaction.After gets cooled need to add required sodium silicate solution and kept one day undisturbed to reach equilibrium state. Consequently, which limits the use of geopolymer in practical cast in-situ applications unlike OPC. Many research has been conducted to develop the one-part geopolymer which means the solid source itself contains alumino silicate source and alkali silicate solid while preparation we just need to add water like OPC. The solid source preparation may require temperature for activating the reactive species and the admixture have to be mixed with the dry sources. The GGBS added geopolymer hardening is slower with the solid activator solution compared to the liquid activator. The mechanical strength is reported to be similar or lower than the two-part geopolymer. Many works have been reported in the development of one-part geopolymer production by varying sources, activator and method. Most of the works related to develop the solid sources with activator but that is not much effective as conventional geopolymer production because of the lack of silicate network species formation in solid activator with water. So, this project work aims to optimize the one-part alkaline solution for the geopolymer production with low alkalinity to takes place geopolymerisation and to make the user-friendly practices in the field condition. This work also aimed to study the life time and stability of the one-part alkaline solution using chemical characterisation, microstructure and kinetics studies.
Objectives:
To develop the one part alkaline activator solution for room temperature cured geopolymer preparation using industrial wastes fly ash and GGSB as aluminosilicate sources.
To optimize alkaline activator with low alkalinity to obtain geopolymer composites with required like workability, compressive strength and thermal resistance.
To understand the effect of Na2O, SiO2 and Al2O3 content from alkali solution, and aluminosilicates in the reaction and mechanism.
To assess the lifetime, species equilibrium and stability of the one part alkaline activator solution.
To characterize the material to understand the reaction kinetics, microstructure and binder gel formation.
Durability assessment of the developed geopolymer composites acid sulphate resistance, carbonation and corrosion ultimately assess the life cycle.