Effects of characteristic hydrates on the pore structure and fracture behavior of CAC bonded alumina-spinel castables
Wenjing Liu, Ning Liao, Mithun Nath, Yawei Li, Yajie Dai, Liping Pan
Abstract
In the present study, the characteristic hydrates (CAH 10 , C 2 AH 8 , and C 3 AH 6 ) were evaluated at individual curing temperatures (10 °C, 25 °C, and 40 °C), and the influences of these characteristic hydrates on the pore structure and fracture behaviors of alumina-spinel castables were systematically investigated. The results revealed that the specimens cured at 10 and 25 °C showed refined and complicated pore structures (higher fractal dimension) after treatment at 1600 °C owing to a higher dispersion of CaO and closely interlocked CA 6 structures. In comparison, the enhanced hydration degree at 40 °C (mostly C 3 AH 6 ) had no positive effect on the formation of nano-pores. Consequently, the generation of plate-like C 2 AH 8 at 25 °C contributed to higher bonding strength after demolding and firing. The optimized microstructures facilitated cracks propagation within the matrixes and along aggregate-matrix interfaces, improving the toughness of castables and obtaining optimal comprehensive properties.