Cambridge University, in partnership with private industry, has made significant advancements in the field of 3D printing by creating a concrete infrastructure unit that incorporates self-monitoring sensors. This groundbreaking project aims to develop a structure that is not only quick to build but also capable of self-repair in the future. Often overlooked, these civil engineering components play a vital role in our road networks, providing stability, support, and controlling the flow of water.
One particular structure of interest is the headwall, a retaining wall with an opening that is placed at the entrance of a drain or culvert. Its primary function is to anchor the culvert and prevent the erosion of surrounding soil caused by running water. Additionally, it provides structural support to adjacent bridges and roadways.
Cambridge University has introduced innovative techniques to enhance the construction of a headwall installed on the A30 in Cornwall. They utilized an onsite robotic 3D printer arm, which quickly laid down layers of fast-setting concrete that hardened within just one hour. However, what sets this project apart is the incorporation of lidar technology during the printing process. The lidar unit scanned the structure, creating a digital twin that can be used as a reference for comparison. sensors
Furthermore, wireless were embedded in the wet concrete to monitor temperature, strain, pressure, humidity, electrical resistivity, and electrochemical potential. The team was particularly interested in monitoring temperature as fast-setting concrete generates significant heat during the hardening and curing process. This innovation eliminates the need for conventional steel reinforcement and allows the structure to rely solely on its geometry for strength. This is a challenging task, especially for a structure with a hollow and curving interior wall.
Led by Professor Abir Al-Tabbaa from the University of Cambridge Department of Engineering, the experiment aims to assess the stability of the 3D-printed structure using the collected sensor data and digital modeling. The goal is to make the structure more appealing to the industry by demonstrating its reliability, robustness, accuracy, and longevity. In addition, the team is also developing a self-healing concrete that could be incorporated into future projects.
The project is considered a living laboratory that will generate valuable data throughout its lifespan. Al-Tabbaa stated that the sensor data and digital twin will provide valuable insights for infrastructure professionals, helping them understand the potential applications of 3D printing for larger and more complex cement-based materials in the strategic road network.
This collaboration between Cambridge University and private industry showcases the potential of 3D printing in the construction industry. The development of self-monitoring and potentially self-repairing structures has the potential to revolutionize civil engineering practices, making construction faster, more cost-effective, and more resilient to environmental factors. As the project progresses, further advancements and applications of 3D printing technology are expected to emerge, benefiting both the industry and society as a whole.
