This book reviews methods for the experimental determination of concrete toughness and presents theories and models suitable for describing cracking and fracturing phenomena in plain and reinforced concrete. Test methods based on classical linear elastic fracture mechanics cannot be applied to laboratory sized concrete specimens. The book compares the currently used methods and presents recommended test procedures for mode I fracture toughness using notched-beam and other specimens. Crack propagation under mixed-mode loading (Mode II) is discussed and current test methods are extensively reviewed. Effects of loading rate, temperature and humidity effects are treated in a separate chapter. The book concludes with descriptions of and recommendations for techniques for detecting the fracture process zone in concrete, in particular, acoustic emission, pulse velocity and laser interferometry techniques. The introduction of the concepts of fracture toughness and fracture energy into structural concrete design codes means that the experimental determination of fracture properties is ceasing to be an academic exercise and is becoming a technical need.
This book has been prepared by RILEM Technical Committee 89-FMT and will be valuable for materials and structural engineers involved in this important transition. The book has over 300 references and 140 line diagrams.