A Numerical Approach to Crack Control in Continuously Reinforced Concrete Pavements

Given the research and practical application of continuously reinforced concrete pavements (CRCP) over the last decades, a variety of design guidelines and practical construction methods are known. Nevertheless, there is still a lack of acceptance of CRCP as a common construction method in Germany. This is partly based on missing research experience on individual in-situ conditions and crack propagation. The potential of CRCP in terms of a longer service life with reduced maintenance and service intervals without cost increase compared to conventional pavement constructions is undisputed; life cycle assessments and the carbon footprint are comparable or even better. Open questions in recommendations are raised on individual conditions, such as construction dates and environmentally friendly concretes. To gain deeper insight into these major factors, a coupled hydrothermal and fracture mechanical model was used in a numerical campaign. The 2D model developed replicates a typical CRCP design in longitudinal direction to focus on transverse cracking, and accounts for concrete creep, bond and friction to provide a realistic representation of the CRCP behaviour. The model is capable to predict the temperature field development regarding hydration and changing ambient temperatures. Parametric studies were conducted varying the hydration behaviour and the time of construction within a day and season. The prognosed stress field induced by temperature changes and shrinkage allows for a consideration of crack initiation to identify critical conditions.