Damage evolution in limestone calcined clay cement (LC3) paste containing recycled glass powder exposed to elevated temperatures

초록

Using the physicochemical effects of recycled glass powder (RGP) is efficacious for improving the high temperature resistance of limestone calcined clay cement (LC3). This study heated LC3 pastes containing RGP to 105, 300, 550, and 900 degrees C. X-ray diffraction, Fourier-transform infrared, Scanning electron microscopy, Mercury intrusion porosimetry, and Thermogravimetric analysis were used to investigate the evolution of their hydration products and microstructure. Surface morphology, compressive strength, and ultrasonic pulse velocity were used to detect the effect of RGP on macroscopic properties. The synergistic effect between RGP and LC3 was confirmed by comparison with previous studies and analysis of oxide composition. At high temperatures, RGP transitions from a glassy state to a viscous state. Before and after the glass transition, the RGP acts as a strength enhancement point effect and binds the microstructure. This enhances its strength at 550 degrees C and 900 degrees C by providing stable support and bonding microstructures. At 900 degrees C, a synergistic effect was produced between RGP and LC3, promoting the crystallization of gehlenite and wollastonite while reducing calcium silicate. The changes in the proportions of Ca, Si, and Al phases determine the composition and quantity of these crystalline phases.

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