Residual compressive strength and mineralogy of LC³ cements exposed to elevated temperatures

ABSTRACT

This study aimed to evaluate the residual compressive strength of LC³ cement mortars after exposure to high temperatures (200, 400, 600, 800, and 1000 °C), in comparison to a Portland cement (PC) mortar. Concurrently, the effect of temperature on the mineralogy of both compositions was assessed using X-ray diffraction (XRD) analysis. The compressive strength results revealed that LC³ cement-based mortars exhibited mechanical performance equivalent to PC-based mortars after 28 days of hydration, regardless of the tested temperatures (23, 200, and 320 °C). Additionally, XRD results indicated that even with the decomposition of ettringite and AFm phases starting at 200 °C, there were no reductions in the compressive strength of LC₃ systems up to 320 °C. The formation of ghelenite phase was identified in LC³ systems at temperatures above 800 °C. This study demonstrated that LC₃ systems displayed mechanical behavior equivalent to PC when subjected to high temperatures. These findings offer significant contributions to the validation and potential practical application of this environmentally-friendly alternative cement.

Keywords
cement; LC³; temperature; X-ray diffraction