To widen the understanding of tensile failure of reticulated ceramic foams and expand the available mechanical method, a cylindrical splitting test is developed in the present study based on alumina open-cell foams of three different pore densities. The biaxial method is validated by characterization of mechanical parameters, and the in-situ fracture process is validated by a digital image correlation, followed by a formula correction for effective tensile strength with consideration of discrete crack paths. For experimental setup curved loading platens, compliant pad and intermediate quasi-static loading rate are proposed for guaranteeing tensile failure under a radial compressive load. Tensile strength, fracture energy, and brittleness increase with the foam pore density, and the fracture behavior is a balanced result of materials and foam structural support strength. An analytical model of splitting tensile strength with structural parameters is derived, which implies its dependence on cell size and critical stress intensity factor of strut materials.

Cement rotary kilns using refractories require excellent refractoriness, thermal shock stability and corrosion resistance due to the cyclic rotation and feeding–discharging of cement clinker. In this paper, a kind of magnesia–alumina spinel refractory containing coating structured aggregates were prepared by wrapping spinel fines on the surface of magnesia aggregates. The fracture behavior and corrosion resistance of prepared refractories were characterized by three-point bending test combined with digital image correlation, acoustic emission technique, and static slag resistance method. The results indicate that by changing the distribution of spinel to make coating structure aggregates, the alumina content is effectively reduced while a more uniform and extensive distribution of spinel phase is achieved. Compared with the merchant magnesia–alumina spinel refractory (10% Al₂O₃) with pre-synthetic spinel aggregates, the magnesia–alumina spinel refractory (5% Al₂O₃) with spinel coating aggregates has the improved mechanical strength and corrosion resistance, and maintains the thermal shock resistance.