Elastic properties of high alumina cement castables from room temperature to 1600°C

Abstract

High-alumina refractory castables with compositions in the systems CaO–Al 2O 3 and CaO–Al 2O 3–SiO 2 were studied using an ultrasonic technique. The technique allows in-situ, non-destructive measurement of Young's modulus from room temperature to 1600°C. Elastic and dilatometric properties were investigated in relation to phase changes (followed by XRD) and sintering phenomena. The conversion of CAH 10, the hydration of still-anhydrous cement phases, and the dehydration of C 3AH 6 and AH 3 are related with events in Young's modulus evolution. Addition of 1 wt% of silica fume strongly decreases the high-temperature mechanical properties.