Experimental investigation and micromechanical modeling of mechanical and durability properties of concrete based on shells from sediments

Abstract

The effect of substituting coarse aggregates with Corbicula shells on the mechanical and durability properties of concrete is evaluated by combining experimental investigations and micromechanical modeling. While substituting 20% of the aggregate volume with Corbicula shells does not affect slump, porosity, carbonation or chloride diffusion, a total replacement decreases slump, increases porosity and carbonation depth. Regarding mechanical properties, Young’s modulus and compressive strength decrease linearly with the incorporation rate of Corbicula shells. The shells are then modeled as non-spherical inclusions surrounded by an interfacial transition zone and embedded in a cementitious matrix, so that micromechanical models provide estimates of mechanical and diffusion properties. Combining the model and experimental results reveals that the low stiffness and drop in compressive strength of the concrete are explained by a weak adhesion between the shells and the cementitious matrix.