Flexural Behaviour of Normal Strength Concrete using Sea-Shells as a Filler at Elevated Temperatures

Abstract

Seashells are one of the many pollutants that are rapidly accumulating on the Arabian Sea’s shores in Karachi, Pakistan, polluting the ecosystem. Seashell (SS) trash, which causes a variety of diseases and is detrimental to the environment, can be used in place of fine aggregate in concrete (0, 10, 20, 30, and 40%) to generate an eco-friendly normal strength concrete (NSC). Due to fire, concrete materials are exposed to higher temperatures over their service life. After a fire, the properties of concrete become extremely important in terms of building serviceability and occupant safety. As a result, seashell trash, which is likely a thermally degradable fiber, was used to improve the fire resistance of normal strength concrete. The mechanical properties of modified and control samples, such as flexural strength, compressive strength, stress-strain response, and mass loss, as well as the deterioration caused by elevated temperatures exposure, were investigated. The studied samples were heated at a rate of 5°C/min to temperatures of 200°C, 400°C, 600°C, and 800°C before being tested for residual conditions. When compared to control samples at elevated temperatures, seashell modified samples had stronger flexural strength, compressive strength, and more mass loss, as well as less spalling sensitivity. When compared to NSC, SS-NSC demonstrated less cracking at higher temperatures, according to visual inspection. To conclude, using seashell in normal strength concrete is effective for both eco-friendly and fire-resistant concrete.