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

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.

Automated summary

The effects of substituting coarse aggregates with Corbicula shells on the mechanical and durability properties of concrete are evaluated through experiments and micromechanical modeling. Partial substitution does not significantly impact key properties, but complete substitution results in decreased slump, increased porosity, and increased carbonation depth. The mechanical properties of the concrete, such as Young's modulus and compressive strength, decrease linearly with the incorporation of Corbicula shells. Micromechanical models reveal that the weak adhesion between the shells and cementitious matrix explains the reduced stiffness and compressive strength of the concrete.