Hempcrete as low carbon solution for thermal retrofitting of buildings

Thermal mortars are developed with hemp shives and pozzolans for thermal retrofitting of cultural heritage buildings, including concrete architecture from the 50s. The goal is to improve the thermal performance of the building, while reducing the carbon footprint. This research is within the framework of European Union’s Horizon 2020 (Sincere). A range of mixtures were developed based on standard mortar for plaster, as a reference. The research investigates the possibility of partly replacing the cement with pozzolans, as well as the sand in the mortar with fine hemp shives, to obtain lower EE and EC of the mixture, as compared to the reference. Replacing 60% of the cement with pozzolans improves the compression strength. Replacing the sand with several percentages of fine hemp shives reduces the compression strengths, while expected to significantly improve the thermal conductivity of the mortar.