Physicochemical, mineralogical, and mechanical properties of calcium aluminate cement concrete exposed to elevated temperatures

One commonly used cement type for thermal applications is CAC containing 38–40 % alumina, although the postheated behavior of this cement subjected to elevated temperature has not been studied yet. Here, through extensive experimentation, the postheated mineralogical and physicochemical features of calcium aluminate cement concrete (CACC) were examined via DTA/TGA, X-ray diffraction (XRD), and scanning electron microscopy (SEM) imaging and the variation in the concrete physical features and the compressive strength deterioration with temperature rise were examined through ultrasonic pulse velocity (UPV) values. In addition, other mechanical features that were addressed were the residual tensile strength and elastic modulus. According to the XRD test results, with the temperature rise, the dehydration of the 𝐶3𝐴𝐻6 structure occurred, which, in turn, led to the crystallization of the monocalcium dialuminate (𝐶𝐴2) and alumina (𝐴𝑙2𝑂3) structures. The SEM images indicated specific variations in morphology that corresponded to concrete deterioration due to heat.