This book is about the relationship between structure size and crack propagation during mechanical loadings. It is commonly accepted that there is a size effect on the nominal resistance of quasi-brittle materials such as concrete. This effect must be taken into account when designing the ultimate behaviour of concrete structures in order to avoid excessive damage and crack openings. Presented here is an experimental method to determine crack openings using the digital image correlation technique, which is a robust and highly precise tool for measuring fracture such as crack opening and crack...