Specimen size effect on fracture toughness for a low cement refractory

• Published in: Theoretical and applied fracture mechanics Vol. 22; no. 1; pp. 51 - 61
• Main Authors: Palmer, G.B., Baker, G.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Ltd 1995; Elsevier
• Subjects: Applied sciences; Buildings. Public works; Cement concrete constituents; Cements; Exact sciences and technology; Materials; Properties and test methods; Properties of anhydrous and hydrated cement, test methods; Fracture mechanics; Refractory cement; Size effect; Experimental study; Brittleness; Strength; Fracture toughness
• ISSN: 0167-8442; 1872-7638
• DOI: 10.1016/0167-8442(94)00048-6

The structural size effect is known to affect failure that is controlled by two regions. The first is dominated by a constant stress at failure ductile behaviour, whereas the second follows classical LEFM brittle behaviour. The transition region between represents the greatest interest with respect to size effect in quasi brittle materials. This paper presents experimental data for a low cement refractory pre-fired to 1200°C (but tested at ambient conditions), showing that specimens do exhibit a size effect, and that typical sizes used in the process industry often lie in the nonlinear transition region. Fracture toughness has been shown to vary as a function of specimen size until the material displays brittle characteristics at which point fracture toughness appears to be a constant material parameter.