Gilbert Achard

Integration of the recycling processes to the life cycle analysis of construction products

Abstract The life cycle analysis of a product enables one to assess its environmental quality. A simple, transparent method taking into account the processes of recycling in the life cycle is developed here. It permits dealing with all types of open loops of all sectors. The principles on which the proposed method is grounded are discussed.

Thermal coupling between the ground and slab-on-grade buildings

Abstract A study of the thermal coupling between a slab-on-grade floor and the ground is presented. This configuration represents only a particular case of a more general problem which is the thermal coupling of a building with the ground, but its frequent occurrence is sufficient to justify this study. An analytical method is used to solve the steady state regime in a two-dimensional (2D) case, and an extension to the three-dimensional (3D) one is developed, taking into account the real geometry of the problem. Then, from some characteristic results previously obtained, we propose a non-steady state solution using a harmonic and impulsion transfer method. Finally, this treatment has been successfully introduced into a more general simulation code of the thermal behaviour of buildings (TONY). The results presented here enable us to establish the validity of the analysis and demonstrate its pertinence. They show the influence of the slab-on-grade on weekly energy needs for two typical French climates, compared with the energy needs for a crawl space configuration.

Using plastic waste as thermal insulation for the slab-on-grade floor and basement of a building

Abstract Experimental and theoretical studies were performed to investigate the possibility of substituting traditional insulation materials with a rigid manufactured polyethylene packing waste. This procedure is of economic interest and contributes to the protection of the environment, since the disposal of plastic waste consumes energy and results in emissions of pollutants to air, water and soil. The first part involved the measurement of the thermal characteristics of the plastic waste using a non-isothermal procedure, based on the transient state of temperature. Two methods were employed: the heat wire method and the ring sensor method. In the second part, a comparative study was carried out for different building configurations using the traditional insulation or the rigid manufactured polyethylene packing waste. The effect of the water table on a building with a rectangular slab-on-grade foundation or with a basement was studied. An analytic method and a commercial software, which uses the finite difference method in two and three dimensions, were used for the comparison. For all configurations, the quantitative values of the heat loss through the ground from the building floor demonstrate the effective performance of the rigid polyethylene packing waste insulation and substantiate the pertinence of its use.