Research of energy efficient structural and composite materials

Abstract

The mechanical and thermal properties of lime-hemp concrete (hempcrete) made in three different mixtures were analyzed in the paper. These mixtures were prepared with a binder-to-filler (hemp and flax shives) ratio of 2.2:1, using quicklime as the primary binder. Some mixtures included a blend of binders, with 10% lime substituted by either cement or organic sapropel. The research findings were compared with those described in our previous research. Research of limehemp concrete has shown - that for the mixtures prepared using binders and filler (hemp and flax shives) with a ratio 2.2: 1 hempcrete has a higher density compared with hempcrete than filler-only hemp shives. The results of the compressive strength testing have shown when flax shives were added to the mixture the strength significantly increased. Then part of the quicklime was replaced by cement (10%) the strength was slightly increased in hempcrete with hemp shives and drastically decreased the compressive strength than filler hemp and flax shives. The results of the thermal conductivity test show that hempcrete with a higher proportion of binder by weight has the highest conductivity, but that concretes with a sapropel admixture have a lower thermal conductivity. The mixtures prepared using binders and filler (hemp and flax shives) have higher conductivity compared with hempcrete than filler-only hemp shives