Improving the Behaviour of Green Concrete Geopolymers Using Different HEMP Preservation Conditions (Fresh and Wet)

Abstract

This paper evaluates a type of geopolymer concrete that uses hemp fibres as a natural aggregate due to the various advantages offered by these woody materials. These advantages include ease of cultivation and processing and their use in the essential structure of concretes used for green construction purposes. The sampling study was prepared using an environmentally friendly inorganic binder, based on geopolymerization reactions (Si-Na). The improvement in the hemp aggregate using two different preservation methods (fresh and wet) was assessed. The type of conservation enables anaerobic reactions to take place in the structure of the hemp, in such a way as to modify the proportions of the organic compounds contained in the hemp and the morphology of the fibres. It also encourages the proliferation of cellulose nanofibrils (CNC), which enhance the mechanical results, improving plasticity and thixotropy. The hempcrete studied in this paper could be a good alternative material for sustainable, environmentally friendly construction, as much less CO2 is emitted during the production process in comparison with conventional concrete. Using wet-preserved hemp means that less water must be added to the mix during preparation of the concrete. This also helps reduce production costs, and by extension, the cost of the final product. © 2022 by the authors.