Recent events of bridge collapses, e.g. in Genoa (Italy) on August 14th 2018 and in Kolkata (India) on September 4th 2018, have focused the public interest on the infrastructures’ safety for their consequences in terms of fatalities and injuries, but also of economy and social losses. Indeed, focusing on reinforced concrete structural components such as beams, they are subjected during their service life to different loading conditions that may affect their durability and efficiency. This can reduce the structural safety over time until its complete degradation up to the ultimate limit state. In particular, reinforced concrete elements can develop cracking conditions due to tensile stresses that are normally absorbed by the reinforcement. However, such cracking conditions can develop and propagate leading to the exposure of the reinforced concrete element to the aggression of external agents such as chlorides up to collapse. In this work, collapse tests on reinforced concrete beams are reproduced in laboratory through nonlinear numerical simulations. The numerical outcomes will be also compared to available monitoring data collected by distributed fiber optics sensors and image correlation techniques to monitor the state of cracking and its propagation in the thickness.