Study of mechanical properties and microstructure of mortars based on oyster shell powder

Abstract

This paper aims at valorise oyster shell co-products in mortars. Oyster shell are calcareous porous materials. Consequently, their use could improve the thermal insulation properties of the concrete. In order to qualify the impact of oyster shell on mortar properties, the influence of the incorporation of oyster shell powder (OS) as a substitution of sand was studied. Mortars made by replacing a part of the sand (0 – 30 – 60 %wt) by shell powder were characterized in terms of mechanical properties and microstructure. The study revealed that the substitution of sand with OS induce a decrease of their mechanical properties. This effect can be explain by higher porosity of 56% increase with 60% OS substitution compared to the reference. Open porosity measurements are confirmed by the reduction of the wave velocity by ultrasonic measurement and microscopic observations revealing smaller pores for shell based materials.