This project focuses on detailed studies of how the cracking process in concrete is influenced by the concrete micro- and mesostructure. The aim is to increase knowledge of how critical parameters affect the cracking process and how this is related to the material's macroscopic properties. A methodology based on the combination of different experimental methods and measuring techniques at different scale levels has been developed. Crack propagation during tensile loading of small-scale specimens in a tensile stage was monitored by means of Digital Image Correlation (DIC) and Acoustic Emission (AE). After the test, crack patterns were studied using fluorescence microscopy.