The thermal performance of lime hemp concrete (LHC) with alternative binders

Abstract

This research studied the influence of replacing the lime with alternative unfired binders on the thermal performance of Lime-Hemp Concrete (LHC), and compared it to conventional building materials, e.g., Autoclaved Aerated Concrete (AAC), Hollow Concrete Blocks (HCB), and Expanded Polystyrene (EPS). This was done by monitoring the internal temperature and relative humidity (RH) of test cells built with LHC and conventional materials, under real-time measured outdoor conditions, during summer and winter. It was found that all LHC cells with and without the alternative binders presented similar behavior, in terms of temperature as well as relative humidity. This means that LHC with alternative binders requires similar quantities of operational carbon (OC) and operational energy (OE) as LHC with 100% lime; however, its embodied carbon (EC) and embodied energy (EE) are relatively lower so in total it requires less energy and is responsible for less CO2 emissions. As for the comparison with conventional building materials, AAC performs slightly better than LHC in the winter, but LHC performs better in the summer, while both AAC and LHC demonstrate better performance than HCB and EPS, in terms of temperature as well as relative humidity. It can be concluded that since LHC possesses relatively lower EC and EE as compared to conventional building materials, it has advantages in terms of energy savings, as well as CO2 emissions.