Evaluation of the thermal performance parameters of an outside wall made from lignocellulosic sand concrete and barley straws in hot and dry climatic zones

Abstract

This study is a continuation of a previous work undertaken on the development of a sand concrete lightened by lignocellulosic materials (wood shavings and barley straws), which is intended for the construction of outside walls. This article aims to evaluate the thermal performance parameters of an outside wall made from lignocellulosic sand concrete and barley straws, in hot and dry climatic zones, such as Laghouat city, south of Algeria. The reference wall (wall 1) is determined by studying the effect of the wall thickness and addition of air–gap. The proposed hypotheses are: double air–gap (wall 2), outside air–gap replaced by barley straws (wall 3), inside air–gap replaced by barley straws (wall 4), both air-gaps replaced by barley straws (wall 5). The objective is to target the best way to build this wall. The experimental study is devoted to determine the thermo-physical properties of the barley straws. The numerical simulation, performed using EnergyPlus software, is used to study the thermal performance parameters of the studied walls, namelythe time-lag, the decrement factor and the average inside surface heat flux. The results show that the proposed hypotheses have clearly improved the outside walls thermal performance parameters, especially the (wall 5) for all orientations. The time-lag is increased by 4 h for the south wall compared to (wall 1), the decrement factor is decreased by 83% and the average inside surface heat flux is decreased by 22%. In addition, the thermal performance parameters of (wall 5) are significantly the best for all orientations compared to hollow brick double wall (wall 6) and cinderblock double wall (wall 7), which are currently used in residential constructions.