Effective thermal conductivity of a gypsum mortar using harbor sediments

Abstract

For sustainable use of natural resources, marine sediments areregularly dredged. One of the valorization ways of thesesediments is to reuse them as raw materials for the formulation of civil engineering products.This paper presents a thermal homogenization methodology for the optimization of heat transfer in Gypsum Plaster Boards formulation using dredged marine sediments. An up-scaling or homogenization technique that links macro- to micro thermal conductivity is given. Effective homogenized thermal conductivity formulation could be presented for a composite material on which a periodic micro-scale heat flux was subjected. For that purpose, steady state balance equations and Fourier heat law were used. Then, a thorough characterization of grain size distributions of dredged sediments were carried out. This showed that the dredged sediments are mainly sandy. Finally, ANSYS Finite Element Code is used to numerically compute the effective homogenized thermal conductivity of Gypsum-sediment composite incorporating different volume fractions of sediments. These simulations, performed on the Representative Volume Element, allowed studying the influence of the sediment grain size. The numerical simulations results, compared to classical theoretical models, have demonstrated the reuse feasibility of investigated sediment in Gypsum Plaster applications.