The Analysis of Concrete Fracture by the Numerical Method – The M?hr-Coulomb versus the Kupfer-Hilsdorf-Rusch Failure Criteria

Abstract

Concrete is a heterogeneous material consisting of aggregates embedded in a cement-sand matrix (mortar). The compression behavior of the aggregate is linear up till failure and the mortar is a brittle-linear material, with a reversible deformation up to its limit, followed by a sudden failure. The resulting concrete demonstrates a quasi-ductile behavior with a progressive decrease in load bearing capacity under incremental monotonic loading. The fracture mechanism of plain concrete on the other hand, is highly influenced by the bond strength in the interface and the tensile strength of the mortar. A Finite Element Model (FEM) was developed for analyzing the fracture characteristic of concrete in flexure. Two failure criteria were evaluated, the Mӧhr-Coulomb envelope and the Kupfer-HilsdorfRusch criteria. The program was validated by experimentally tested specimens, and proven to be accurate. Further, this program served as tool to analyze the fracture response of a range of concrete strengths. This research work was conducted at the Structural and Material Laboratory, Diponegoro University in Semarang, Indonesia. Keywords-component; fracture, tensile strength, FEM, failure criteria