Effect of Doum and Polypropylene Fibres on the Physical and Thermomechanical Properties of Stabilized Earth Blocks (SEBs)

Abstract

Earth-based materials are increasingly recognized as sustainable and low-energy alternatives to conventional construction materials. However, stabilized earth blocks (SEBs) often suffer from low tensile strength and limited durability, which restrict their structural applications. Fibre reinforcement has proven to be one of the most effective methods to enhance their mechanical and thermal performance.

This research investigates the combined effect of Doum fibre (DF) and Polypropylene (PPF) fibres on the physical and thermomechanical properties of stabilized earth blocks (SEBs) produced from local Algerian soils. The mix design consisted of 70% soil, 20% dune sand, and 10% cement, while Fibre content was varied at 0.1%, 0.2%, 0.3%, 0.4%, and 0.5% for both Doum fibre (DF) and Polypropylene (PPF). The blocks were compacted under a pressure of 2 MPa and cured for 28 days under controlled laboratory conditions. The results reveal that fiber inclusion significantly alters SEB performance, with optimal improvements observed at 0.4% for DF and 0.3% for PPF. While PPF-enhanced SEBs consistently demonstrated superior mechanical properties—such as higher compressive and tensile strength, and UPV—DF-reinforced SEBs exhibited better thermal conductivity. These findings highlight the potential of fiber-reinforced SEBs for sustainable construction, with fiber type and dosage playing a critical role in tailoring material performance to specific functional requirements.