ABSTRACT
ABSTRACT: The aim of this paper is to quantify crack initiation in two types of concrete containing alkali-activated binder. Beam specimens with a stress concentrator were tested via three-point bending after 28 and 90 days of maturing. The fracture tests were recorded in the form of load versus mouth crack opening displacement (P-CMOD) diagrams, which were evaluated using the Double-K fracture model. This model allows the quantification of two different levels of crack propagation: initiation, which corresponds to the beginning of stable crack growth, and the level of unstable crack propagation. The initiation of cracks during the fracture tests was also monitored via the acoustic emission method.
