Évaluation du confort thermique dans des constructions isolées thermiquement par différents types de matériaux

Abstract

This study aims to develop and characterize innovative biocomposite materials using waste plant compounds and commonly found wastes in Algeria for effective thermal insulation in civil and mechanical engineering applications. The goal is to create materials with mechanical and thermo-physical properties equal to or surpassing those of traditional construction materials, thereby reducing environmental impact and construction costs while promoting sustainable waste management practices. In the first place, Date palm leaflet waste (DPF) is used as reinforcement, and melting polystyrene (PS) is used as a matrix. Three categories of fibers, untreated fiber (UDPF), alkalinized fiber (ADPF), and benzoylated fiber (BDPF), are employed to create samples with fillers of 10%, 20%, and 30% (by weight). The composites were produced using the melt-mixing method and hot compression molding. In this study, various morphological, mechanical, and thermophysical tests were conducted on the composites to assess their potential as thermal insulators. The bulk density, pore size, and distribution of the fibers and composite were assessed using the Mercury Intrusion Pore Measurement method (MIP). Tensile and three-point bending tests were performed using a traction machine type INSTRON 5969. The thermal conductivity was measured using a CT-meter device. Results show that Alkalinization and benzoylation treatments improved the interfacial interaction between the hydrophilic fibers and the hydrophobic polystyrene, as confirmed by SEM and FTIR analyses. XRD studies indicated the highest crystallinity index for ADPF. The results of PS-DPF composites demonstrated satisfactory tensile and flexural strength of 14–44 MPa, The chemical treatments enhanced strength while slightly decreasing modulus (2.9–5.9 GPa). Thermogravimetric analysis revealed increased thermal stability for composites with 30% untreated and treated fibers. These composites exhibited low thermal conductivity (0.118–0.141 W/ (m.K)) and decreased bulk density after incorporation fibers (860 -980 kg/m3). Replacing one-third of conventional building materials with PS-DPF composites showed a reduction in thermal conductivity by up to 50%, highlighting their potential in thermal insulation applications. The second research endeavor explores the valorization of common wastes—date palm petiole fibers (DPP) and expanded polystyrene waste (EPS)—to elaborate a gypsum plaster hybrid biocomposite. Hand-made samples with varying DPP mass loadings (0%, 5%, 10%, and 15%), EPS mass ratios (0.3%), or both were examined through morphological, mechanical, and thermophysical tests. Despite a reduction in mechanical properties, the hybrid biocomposites exhibited lower thermal conductivity of 0.2645-0.425 W/ (m.K) and bulk density of 852-977 kg/m3 compared to neat gypsum plaster (NGP). The study positions gypsum plaster reinforced with DPP, EPS, or both as a potential alternative to traditional insulation materials, offering a sustainable solution for construction purposes