Durabilité des mortiers en terre stabilisée

Abstract

Throughout ancient times, earth mortar was a fundamental construction material across various civilizations due to its widespread availability, cost-effectiveness, and advantageous thermal comfort characteristics. Today, amidst increasing global concerns such as escalating energy demands and heightened carbon dioxide emissions, the study of earth-based construction methods is gaining renewed relevance. This study aims to optimize the formulation of earth mortar, a fundamental material in traditional earthen construction, through a systematic approach. Particular emphasis is placed on evaluating its mechanical, physical, and durability properties to enhance its performance in contemporary sustainable building practices. Central to this methodology is the exploration of date palm ash (DPA) as a potential additive to improve the performance of earth mortar. To scrutinize the effects of DPA on earth mortar, the study involved preparing samples incorporating lime stabilization alongside varying doses of DPA, ranging from 0% to 10% of the binder. Experimental results demonstrate that incorporating DPA significantly enhances earth mortar properties. Optimal formulations containing 6% DPA exhibited a 40% reduction in linear shrinkage compared to the reference mixture and an 83.4% increase in elastic modulus. In chemical durability tests, this 6% DPA formulation notably improved resistance to aggressive agents, performing well against sodium sulfate and hydrochloric acid, though sulfuric acid presented the most significant challenge. Under accelerated carbonation, the 6% DPA formulation exhibited increased compressive strength and a stable mass gain. Moreover, DPA improved physical and durability properties. SEM and EDX analyses revealed that DPA reduces voids between earth mortar particles and increases C-S-H content, which supports the observed improvements in overall performance. The enhanced properties of earth mortar with DPA supplementation offer notable advantages for sustainable construction. DPA mitigates shrinkage and boosts mechanical strength. Additionally, this approach supports environmental sustainability by effectively repurposing date palm cultivation byproducts, reducing waste, and promoting a circular economy.