An assessment of some physical properties of lime-hemp concrete

Abstract

This work is part of a wider research programme that aims at producing alternatives to conventional building materials. The aim of this project is to investigate several physical properties of a sustainable, carbon-negative, lime-hemp biocomposites which can partially replace existing, non-biodegradable, non-sustainable, building materials of high embodied energy and high CO2 emissions. The shrinkage, flexural and compressive strengths of these lime-hemp concretes, made with either calcium lime or a commercial binder with a cement content and varying lime:hemp proportions (1:9, 1:1 and 3:1), were investigated according to the relevant European standards. The shrinkage and strength development at 7, 28 and 90 days were monitored. The relationship between shrinkage and binder type, hemp content and water content was observed. The development of the flexural and compressive strengths shared several characteristics but their behaviour departed in relation to increasing hemp content with compressive strength continuously decreasing while flexural strength varied little between 50% and 75% hemp content.