HYGRO-THERMAL BEHAVIOUR OF POROUS BUILDING MATERIAL SUBJECTED TO DIFFERENT EXTERNAL TEMPERATURE AND HUMIDITY CONDITIONS

Abstract

This work is focused on the behaviour of a block of cement mortar, subjected to variable external temperature and humidity conditions. The porous building material sample is fitted inside a box, in which a heat exchanger is connected to a thermostatic bath. Three sequences of measurement are considered: (i) the response of the sample, when variations of temperature are applied; (ii) the air ranging between the exchanger and the non-isolated face of the mortar is continuously humidified, by injecting of sprayed water; (iii) the effect of simultaneously variation on temperature and humidity. A mathematical model representative of heat and mass transfer, in multiphasic medium (cement mortar), is developed in order to confront experimental and numerical results. Displacements of moisture and temperature fronts are observed and discussed. This study would enable us to understand the hygro-thermal behaviour of construction walls, to make an adequate design according to the climatic parameters and thus to improve the control of the energy used for heating.

Keywords

• Cement mortar
• Variable conditions
• Experimentation
• Modelling.