ABSTRACT
In this chapter, the authors provide a detailed discussion on the experimental tools. They explain loading techniques, test-control systems and data-acquisition equipment, as well as specimen selection and manufacturing criteria. The authors provide some examples of advanced fracture experiments and also address some of the possible pitfalls in the design of a test set-up. They discuss the choice for a control variable in a four-point shear experiment, in a hydraulic fracture experiment, and in a true triaxial experiment. The authors also discuss in more detail the uniaxial tensile experiment, which is central to fracture mechanics studies of concrete. They focus on frictional boundary restraint, in particular on the effect of boundary restraint in compression tests and three-point-bend tests, as well as on the rotational stiffness of the entire specimen-machine system. The authors describe surface deformation measurement techniques and discuss photo-elastic coating techniques, various interferometry methods and stereo-photogrammetry.
