A new acoustically insulating fiber-reinforced lightweight concrete based on local materials and date palm waste

Abstract

Purpose This paper aims to characterize and develop a new ecological lightweight concrete reinforced by addition of palm plant fibers (from vegetal waste) to be used in the thermal and acoustical insulation of local constructions. The date palm plant fibers are characterized by their low sensitivity to chemical reactions, low cost and large availability in local regions. Therefore, the newly obtained lightweight concrete may suggest a great interest, as it seems to be able to achieve good solutions for local construction problems, technically, economically and ecologically. Design/methodology/approach The experimental program focused on developing the composition of palm-fiber-reinforced concrete, by studying the effect of the length of the fibers (10, 20, 30 and 40 mm) and their mass percentage (0.5%, 1%, 1.5% and 2%), on the mechanical and acoustical properties of the composite. The main measured parameters were the compressive strength and flexural strength, sound absorption coefficient, noise reduction coefficient (NRC), etc. These tests were also borne out by the measure of density and water absorption, as well as microstructure analyses. To fully appreciate the behavior of the material, visualizations under optical microscope and scanning electron microscope analyses were carried out. Findings The addition of plant fibers to concrete made it possible to formulate a new lightweight concrete having interesting properties. The addition of date palm fibers significantly decreased the density of the concrete and consequently reduced its mechanical strength, particularly in compression. Acceptable compressive strength values were possible, according to the fibers content, while better values have been obtained in flexion. On the other hand, good acoustical performances were obtained: a considerable increase in the sound absorption coefficient and the NRC was recorded, according to the content and length of fibers. Even the rheological behavior has been improved with the addition of fibers, but with short fibers only. Originality/value Over the recent decades, many studies have attempted to search for more sustainable and environmentally friendly building materials. Therefore, this work aims to study the possibility of using waste from date palm trees as fibers in concrete instead of the conventionally used fibers. Although many researches have already been conducted on the effect of palm plant fibers on the mechanical/physical properties of concrete, no information is available neither on the formulation of this type of concrete nor on its acoustical properties. Indeed, due to the scarcity of raw materials and the excessive consumption of energy, the trend of plant fibers as resources, which are natural and renewable, is very attractive. It is therefore a major recycling project of waste and recovery of local materials.