Performance of Residual Properties for High Strength Concrete Incorporating Nanosilica against Temperatures

High strength concrete (HSC) is becoming a material choice owing to its wide range of applications in high-rise buildings, bridges, shells of a nuclear reactor, etc. The residual mechanical properties of HSC post-fire exposure are of great importance in determining the load bearing capacity of structural members required for retrofitting and restoration of the concrete structure. The performance of silica nanoparticles (SN) incorporated HSC has been evaluated under two levels of elevated temperature conditions, 200^oC and 400^oC, by exposing up to determine temperature, followed by cooling to ambient temperature before performing experiments. A reduction in weight loss was observed in specimens after exposure to 200^oC and 400^oC. On exposure to 400^oC for 2 h, the compressive strength increased by 17% and 14.5%, for silica fume SF and SF + nanosilica (NS) specimens respectively. On exposure to 400^oC for 2 h, the splitting tensile strength decreases by 44% and 60.4%, for SF and SF+NS specimens respectively.

SELEEM S.E. AHMAD, Professor, Head of Development
HOSSAM S. KHALIL, Assistant professor
IBRAHIM A. SHARAKY, Lecture
AHMAD M. El-AZAB, Demonstrator

Materials Engineering department, Faculty of Engineering, Zagazig University (44519, Zagazig, Zagazig University, Sharkia, Egypt)

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