Monitoring of earth concrete damage evolution during drying

Abstract

Earth concrete, constituted mainly of raw earth, is a promising ecofriendly material for future constructions. However, it is composed of fine particles like clay which make it very sensitive to drying. The volume change induced by desiccation shrinkage can be responsible of cracking which can have a detrimental effect on the durability and mechanical properties. Thus, in order to design reliable earth concrete structures, considering a coupling between drying shrinkage and damage is important. The effect of curing conditions on the mechanical properties of earth concrete with different percentages of flax fibers has been studied. The evolution of damage during drying has been monitored continuously using the ultrasound and the acoustic emission (AE) techniques. The mechanical properties of earth concrete decreases for specimens stored at low relative humidity. In addition, the AE results associated with shrinkage and mass loss measurement made it possible to describe qualitatively the drying process.