Influence of post-fire recuring regimes on the properties of self-compacting concrete with heavyweight aggregate

Influence of post-fire recuring regimes on the properties of self-compacting concrete with heavyweight aggregate

Článek WoS

Fire safety is essential in construction, as accidental fires subject concrete structures to high temperatures that result in significant damage. This study examines the development of self-compacting concrete (SCC) characteristics with barite heavyweight aggregate (20-100% substitution of natural coarse aggregate) after being exposed to 600 degrees C, followed by several post-fire re-curing methods (water, CO2, water-glass, and air). The property evolution was examined for cracking, density loss, residual compressive strength, and ultrasonic behavior, verified by FTIR, MIP, and SEM-EDX tests. The exposure to 600 degrees C resulted in widespread microcracking, significant mass loss, and decreased strength, besides the severity increasing with higher barite concentrations due to the brittleness and thermal sensitivity of heavyweight aggregate. Post-fire curing demonstrated specific recovery mechanisms: water curing promoted rehydration and achieved partial strength recovery of approximately 75% of pre-fire values; CO2 curing improved densification via carbonation but resulted in increased brittleness; water-glass curing partially filled cracks but decreased long-term stability; and air curing caused additional drying shrinkage and further deterioration. The results highlight the interrelated chemical and microstructural changes that influence the post-fire development of SCC characteristics, revealing that water and CO2 re-curing are the most effective methods for performance restoration.

Fire safety is essential in construction, as accidental fires subject concrete structures to high temperatures that result in significant damage. This study examines the development of self-compacting concrete (SCC) characteristics with barite heavyweight aggregate (20-100% substitution of natural coarse aggregate) after being exposed to 600 degrees C, followed by several post-fire re-curing methods (water, CO2, water-glass, and air). The property evolution was examined for cracking, density loss, residual compressive strength, and ultrasonic behavior, verified by FTIR, MIP, and SEM-EDX tests. The exposure to 600 degrees C resulted in widespread microcracking, significant mass loss, and decreased strength, besides the severity increasing with higher barite concentrations due to the brittleness and thermal sensitivity of heavyweight aggregate. Post-fire curing demonstrated specific recovery mechanisms: water curing promoted rehydration and achieved partial strength recovery of approximately 75% of pre-fire values; CO2 curing improved densification via carbonation but resulted in increased brittleness; water-glass curing partially filled cracks but decreased long-term stability; and air curing caused additional drying shrinkage and further deterioration. The results highlight the interrelated chemical and microstructural changes that influence the post-fire development of SCC characteristics, revealing that water and CO2 re-curing are the most effective methods for performance restoration.

Self-compacting concrete (SCC), Heavyweight concrete (HWC), 600 degrees C, Post-fire-curing, Recovery, Residual performance, Microstructure

Self-compacting concrete (SCC), Heavyweight concrete (HWC), 600 degrees C, Post-fire-curing, Recovery, Residual performance, Microstructure

TAWFIK, T.; PALOU, M.; SOUKAL, F.; KUZIELOVA, E.; PECIAR, P.; GHARIEB, M.; HAMA, S.; SVOREC, J.

14.10.2025

Springer Nature

Scientific Reports

15

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Spojené království Velké Británie a Severního Irska

1

32

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https://www.nature.com/articles/s41598-025-19737-6#citeas