Abstract
Hemp concrete is a sustainable lightweight concrete that became popular in the field of building construction because of its thermal and environmental properties. However; available experimental data on its hygrothermal behavior are rather scarce in the literature. This paper describes the design of a large-scale experiment developed to investigate the hygrothermal behavior of hemp concrete cast around a timber frame through a spraying process; and then coated with lime-based plaster. The equipment is composed of two climatic chambers surrounding the tested wall. The experiment consists of maintaining the indoor climate at constant values and applying incremental steps of temperature; relative humidity or vapor pressure in the outdoor chamber. Temperature and relative humidity of the room air and on various depths inside the wall are continuously registered during the experiments and evaporation phenomena are observed. The influence of the plaster on the hygrothermal behavior of hemp concrete is investigated. Moreover; a comparison of experimental temperatures with numerical results obtained from a purely conductive thermal model is proposed. Comparing the model with the measured data gave satisfactory agreement.
Highlights
Nowadays, a large number of works deal with hygroscopic building materials in order to understand their hygrothermal performance in the building envelope and their interaction with enclosed space
An experimental apparatus is developed and built at the laboratory of material science at the Université de Bretagne-Sud [31] in order to investigate the hygrothermal behavior of a hemp concrete wall
Air temperature and relative humidity are measured in the center of each room with a thermocouple placed inside radiation shield and two capacitive humidity sensors
Summary
A large number of works deal with hygroscopic building materials in order to understand their hygrothermal performance in the building envelope and their interaction with enclosed space. This specific experiment allows investigation of the hygrothermal behavior as a function of combined and controlled heat, air and moisture fluctuations and creating a large database and benchmark for validating HAM models in order to accurately predict energetic behavior and overall comfort All these numerical and experimental methods are largely applied to classical hygroscopic building materials like gypsum, wood panels or insulation, but less to new sustainable materials, like hemp concrete, that may offer large possibilities in the sustainable building construction yet [16,17,18].
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have