Published online by Cambridge University Press: 21 February 2011
A new testing method is presented in which the properties of the bond zone between aggregate and matrix in concrete are investigated. The reason for starting the investigation is the improvement of the lattice model, which is developed at the Stevin Laboratory. In the lattice model the material is schematized as a lattice of beam elements. The fracture properties of the individual beam elements are purely brittle, and the use of fracture energy parameters as a material property can be avoided for simulating the non-linear fracture process. In spite of the fact that a locally brittle law is used, the global behaviourshows softening of the material. An improved optical microscopy technique in combination with image processing is adopted for investigating the fracture process during loading.