Mechanical and durability performance of sustainable concretes containing conventional and emerging supplementary cementitious materials

Abstract

This paper presents a comparative study on the mechanical and durability properties of concrete mixtures containing conventional supplementary cementitious materials (SCMs) and emerging alternatives (i.e., volcanic ash, volcanic ash-limestone blend, and metakaolin-limestone blend), with an emphasis on the latter. To enable effective comparison, identical volumetric substitution levels (30%) of SCMs along with a constant binder and aggregate volumes were employed. The metakaolin-limestone concrete performs the best among all types of concretes in terms of strength development, water absorption capacity and chloride penetration resistance. The incorporation of volcanic ash though reduces the compressive strength of concrete and increases water absorption capacity considerably compared to the reference Portland cement concrete, and its chloride diffusion coefficient is only about half of that of the reference concrete. In addition, the concretes containing volcanic ash or volcanic ash-limestone show better performance in controlling the potential alkali-silica reaction-induced expansion than the reference concrete and ground granulated blast-furnace slag concrete.

Keywords

• Natural pozzolan
• Limestone calcined clay cement
• Chloride diffusion
• Water absorption
• Alkali-silica reaction