Compression behaviour and failure mechanisms of a safety culvert made of hollow high-performance concrete blocks

The safety culvert composed of hollow high-performance concrete blocks is designed to reduce the risk of injury in the event of a collision. This work presents a new design with an opening for water flow, tests it, identifies its weaknesses, and discusses possible improvements. The numerical model is constructed, validated by experiment, and used to study the effect of design parameters on the load capacity, compression behaviour, and failure mechanisms. The response varies most markedly with the opening diameter. The failure mode changes from bending failure to concrete crushing as the diameter decreases. The effect is most pronounced for diameters less than 400 mm, where the load capacity increases by 6 kN per millimetre reduction. If a crack develops in the culvert during its service life, the first such crack will form in the top layer of blocks, followed by a crack in the opening. These areas should be monitored more closely during follow-up tests with passing vehicles.