Effects of seashell aggregates in concrete properties

Abstract

In this project the use of mussel shell as fine and coarse aggregate in concrete is studied. Two different conventional concretes were designed, a non-structural concrete (NSC) and a plain structural one (SC). Then, the conventional fine and coarse aggregate was partially replaced with seashell. Initially, each size fraction (fine or coarse) was replaced separately using four substitution rates (25%, 50%, 75% and 100%). Finally, two low percentages (5% and 12.5%) were chosen to replace both fine and coarse fractions. All concretes (a total of 19 different mixes) were characterized in both fresh and hardened state (workability, compressive strength, longitudinal modulus of elasticity, weight loss and water permeability). The results permit to establish that the percentage of replacement should be limited to 12.5% of fine, coarse, or both fine and coarse aggregate. With this percentage the NSC and the SC, although with a worst performance than their conventional ones, show an accurately behavior.