Published Online:July 2026
Product Name:The IUP Journal of Structural Engineering
Product Type:Article
Product Code:IJSE010726
DOI:10.71329/IUPJSE/2026.19.3.7-22
Author Name:Mahesh B Shirur, B C Shatappa and K B Prakash
Availability:YES
Subject/Domain:Engineering
Download Format:PDF
Pages:7-22
This is an experimental study on high-volume fly ash concrete (HVFAC) at 50-70% fly ash (FA) replacement, subjected to thermal exposure and gradual cooling to check for residual mechanical strength, weight loss and sorptivity analysis. Strength was essentially retained up to 200-300 °C, declined moderately to 600 °C, and fell sharply beyond 800 °C; by 1000 °C, residual compressive strength had fallen to 62-69% of the reference value, split tensile strength to 44-71%, and flexural strength—the most temperature-sensitive of the three properties—to 60-65% of the reference value across the three replacement levels. Sudden cooling produced consistently lower residual strength and higher sorptivity than gradual cooling at common peak temperatures, most markedly for split tensile and flexural strength, consistent with thermal-shockinduced microcracking reported in the literature. The results provide new comparative data across compressive, split tensile and flexural strength at high FA replacement levels (50-70%) and support the use of gradual cooling protocols, where practicable, when managing fire-damaged HVFAC.
Concrete structures may be exposed to sustained high temperatures during accidental fires, industrial furnace linings, or nuclear-containment incidents, and assessing residual load-carrying capacity after such an event is essential for deciding whether a structure can be repaired or must be demolished.