Improved high-temperature resistance of limestone calcined clay cement

Abstract

In this research, the effects of biochar on the evolutions of the LC3's residual compressive strength, cracking, and ultrasonic pulse velocity were investigated after being heated to 300, 550, and 900 °C. The novelty of this study lies in the dual effect of adapting to climate change while optimizing high temperature resistance by encapsulating biochar in LC3. Moreover, an experimental design that applies multiple analytical methods and macro-micro mutual verification. The compositional changes in the hydration products and interface microstructure were analyzed in detail. The results showed that biochar increased the residual compressive strengths and curbed the crack's development. Especially at 900 °C, 1% and 2% of biochar increased its strength by 14.86% and 27.55%, respectively. These improvements may be closely related to the porous structure of biochar. The results of this study provide a valuable reference for the high temperature resistance of LC3 and help to deepen its understanding. © 2024 The Authors