Abstract:
Seashells are one of the numerous wastes that are quickly accumulating onshore coasts on the
Arabian Sea, Karachi, Pakistan causing pollution for the environment. The seashell (SS) waste
that causes various diseases and hazardous for environment can be used in concrete (0, 10, 20,
and 30%) and in plastering mortar (20%, 40% and 60%) in place of fine aggregate to create an
eco-friendly high strength concrete (HSC). Concrete materials undergo higher temperatures
during their service period due to fire. After exposure to fire, properties of concrete have a prime
importance in terms of serviceability of buildings and occupants’ safety. Therefore, to improve
the fire resistant of high strength concrete, seashell waste was included, which is possibly a
thermal degradable fiber. The mechanical properties namely compressive strength, stress-strain
response, elastic modulus, compressive toughness, strain ductility and mass loss of modified and
controlled samples, as well as the deterioration caused by elevated temperatures exposure were
studied. The analyzed formulations were heated to a temperature of 200, 400, 600, and 800°C at
a heating rate of 5°C/min and then tested for residual conditions. Seashell modified samples
showed a higher compressive strength, elastic modulus, compressive toughness as compared to
control sample at elevated temperature with less spalling sensitivity. According to visual
inspection, SS-HSC as compared to HSC showed less cracking at higher temperatures.
Moreover, the effect of plastering high strength concrete with seashell showed greater strength
with more fire resistant to concrete core. Conclusively, utilization of seashell in high strength
concrete is efficient for eco-friendly as well as fire resistant concrete.
