This article presents an experimental device and the procedure used to determine the mass diffusivity coefficient of beech from adsorption/desorption cycles. The experimental device is built around a magnetic suspension balance that is able to achieve accurate mass measurements over a wide range of temperature and relative humidity. The value of mass diffusivity is determined using a slope method from the transient period of relative humidity steps. Experimental values are presented for beech in longitudinal and tangential directions.

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This work focuses on the development of local building materials in Benin for their efficient use in buildings. It aims to make mud bricks lightened with good mechanical, thermal and sound properties and enhance the waste polystyrene. This article is the result of experimental work on a broad field of applied sciences: building mechanics. The study is focused on BTS (blocks of stabilized earth) chosen as reference materials to which we linked polystyrene. The percentage of polystyrene varies from 0% to 100% starting from a constant volume of each reference material. The results showed that the increase in polystyrene percentage lowers mechanical properties. These results also showed that the gradual addition of polystyrene to the laterite-cement mixture has a significant influence on the density and mechanical resistances of the final composite material.

The building represents one of the main actors of global warming of the planet because of the significant amounts of energy consumed. In Benin, 44,38% of electrical energy is consumed by office and service buildings. This is explained by the excessive use of air conditioning systems due to the lack of a thermal comfort index specific to the region. This work therefore focuses on assessing the impact of the choice of a thermal comfort model on the energy efficiency of buildings. For this purpose, an office building was chosen in the south of Benin and comfort surveys were conducted among the occupants. The model selected for this purpose is the adaptive model developed by López-Pérez and al. for air-conditioned buildings in humid tropical regions. Subsequently, a monitoring campaign of meteorological, hygrothermal and energetic data of the building was carried out during six months. The results obtained show that the average temperature of the offices (Tf ≈ 24°C) during the hours of occupancy is relatively lower than the comfort temperature determined with the model (Tc = 26.2°C). Moreover, the different simulations carried out under TRNSYS by substituting the office temperatures by the comfort temperature show a reduction of about 20% of the building’s energy consumption. This shows the importance of the comfort model of López-Pérez and al. in improving the energy efficiency of the building.

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