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This paper presents a theoretical and an experimental study on the determination of thermal phase shift time and damping factors of building walls. The work consisted in evaluating the thermal comfort in a building. This study is a contribution to put in place a thermal regulation in Burkina Faso, a country with a dry tropical climate. This regulation will, in its application, reduce the energy consumption related to air conditioning in buildings. To do this, we theoretically determine the parameters influencing this comfort using the admittance method. This method makes it possible to analyze the thermal response of a building to a periodic energy demand. It is based on the modeling of the building component by the quadrupole method resulting from the writing of the thermal problem in the form of transfer matrix products. The principle is to link the flows and temperatures of both sides of a homogeneous wall through the equation of heat and the Fourier transform. The calculation method is validated by experimental results. For simple sheet walls based on their compositions, damping factors range from about 37.9% to 79.7% and thermal phase shift time from about 3.9 hours to 7.4 hours. However, the values of these parameters are better when the walls are double-sheeted, the maximum value of the damping factor is 11.5% and the minimum value of the thermal phase shift time is 9.7 h. The values of Mean Bias Difference (MBD) and Root Mean Square Difference (RMSD) show that the theoretical and experimental results are quite concordant. The admittance method can be used to evaluate the performance of building walls.

The main objective of this study is to characterize a material, non-autoclaved aerated concrete, referred to as "foamed concrete", newly produced in Burkina Faso. This study made it possible to determine some thermo-physical, mechanical and hygro-thermal properties of foamed concrete. The material was obtained by making a mixture of cement, sand, water and a foaming agent.The tests were carried out with five types of samples having densities between 600 and 930 kg/m 3 and a water content ranging from 22 to 35%. The experimental results obtained show that the studied foamed concrete has a thermal conductivity ranging from 0.05 to 0.2 W/m.K and compressive strength is between 1.2 to 3.4 MPa. The dynamic Young's modulus is between 1.18and 3.1 GPa and the porosity is varying from 55.60 to 72.36%. Analysis of the results show that the incorporation of the foam in the mortar made it possible to have a more insulating material and acceptable mechanical properties for sustainable construction.

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