Modeling of Concrete Cracking Induced by Steel Expansion

• Published in: Journal of materials in civil engineering Vol. 13; no. 3; pp. 169 - 175
• Main Author: Leung, Christopher K. Y
• Format: Journal Article
• Language: English
• Published: Reston, VA American Society of Civil Engineers 01-06-2001
• Subjects: Applied sciences; Building failures (cracks, physical changes, etc.); Buildings. Public works; Concretes. Mortars. Grouts; Corrosion; Durability. Pathology. Repairing. Maintenance; Exact sciences and technology; Materials; Reinforced concrete; TECHNICAL PAPERS; Interface properties; Corrosion mechanism; Stress intensity factor; Physical model; Dimensional analysis; Theoretical study; Cracking; Volume expansion; Reinforced concrete; Dislocation; Crack propagation
• ISSN: 0899-1561; 1943-5533
• DOI: 10.1061/(ASCE)0899-1561(2001)13:3(169)

When steel reinforcement corrodes in a concrete structure, the expansion of corrosion products often leads to cracking in the concrete. In this paper, a simple physical model is developed to relate the size of cracks to steel expansion. By assuming the steel concrete interface to be perfectly smooth or perfectly bonded, upper- and lower-bound solutions can be obtained. The results indicate (1) the presence of an expansion threshold below which no crack propagation can occur; (2) a "pop-in" behavior occurring at a critical expansion that is strongly dependent on initial flaw size; and (3) the steel expansion to generate a given crack size is strongly affected by interfacial bonding. When the theoretical findings are compared to available experimental results, good agreement is obtained. Based on the theoretical results, several guidelines for controlling expansion-induced cracking can be proposed. These include proper control of initial flaw size, addition of fibers to produce an R-curve behavior, and the enhancement of bond and or friction at the steel concrete interface.