Hygro-mechanical properties of wood-aggregate concrete: Experimental study and modeling

To reduce the environmental impact of buildings, light-weight concrete made of renewable aggregates is a promising solution. This work aims to study hygromechanical properties of wood-aggregate concrete (composed of cement paste and wood shavings) upon drying by using both experimental and modeling approaches. To study the effect of the mechanical properties of the different constituents on the hygromechanical behavior of this concrete, we performed compression tests to determine the Young's modulus of the samples and measured shrinkage strains upon drying of mixtures with identical contents of wood but various cement-to-wood mass ratios. To analyze the compression data, we developed a first model based on homogenization theory using the self-consistent scheme which allows to link the evolution of Young's modulus over time with the volume fractions and elastic properties of the various phases of the concrete. A second model coupling desorption-induced strains and water transfer was derived to explain the measured shrinkage strains.