Thermophysical Characterization of an Insulating Bio-material Based on the Macerate of ''Néré'' (Parkiabiglobosa) Pods and Cow Dung

Abstract

This work concerns the thermophysical characterization of a bio-eco-material made from cow dung and the macerate of nere pods. To achieve this, chemical tests based on tannin concentration determination of four different solutions of nere pods (60 g.l-1; 120 g.l-1; 180 g.l-1 and 240 g.l-1) were prepared at 100°C, then brought to the boil for 5 minutes. After three different maceration times (6 h; 24 h and 48 h), the analysis of the solutions obtained using a spectrometer made it possible to select the solutions of 120 g.l-1 and 180 g.l-1 which offer best tannin concentrations in 24 hours, necessary for making test pieces. Thermal tests based on thermal effusivity and thermal conductivity measurements were then carried out in transient mode, with hot strip method. In order to compare the thermal performance of developed eco-material with that of ordinary insulators, the thermophysical properties of plywood and plaster were also measured. The results obtained showed that for the two dosages of 120 g.l-1 and 180 g.l-1, the thermal effusivity of eco-insulator varies from 247.732 J.K-1.m-2.s-0,5 to 270.732 J.K-1.m-2.s-0,5 respectively and the thermal conductivity from 0.082 W.m-1.K-1 to 0.080 W.m-1.K-1. For the same dosages, the thermal diffusivity varies from 1.106.10-7 m².s-¹ to 0.881.10-7 m².s-¹ respectively. A comparative study has shown that the eco-material developed and tested offers better insulating power due to its relatively weak thermophysical properties compared to ordinary insulating materials, namely plaster and plywood.