A Digital Workflow for the Design and Manufacturing of 3D Printed Concrete Bridges in a Circular Economy: Structural Design Considerations for Pre-Stressed Beams and Dry Connections

EngD trainee Rong Yu
Project A Digital Workflow for the Design and Manufacturing of 3D Printed Concrete Bridges in a Circular Economy: Structural Design Considerations for Pre-Stressed Beams and Dry Connections
University supervisor dr. ir. Rob Wolfs and prof. dr. ir. Theo Salet
Company supervisor Eize Drenth & ir. Johan de Boon
Name of company Rijkswaterstaat
Period of project October 2020 – September 2022


Facing the challenges of climate change and growing housing demand, the current architecture, engineering and construction (AEC) industry is suffering from low productivity and high environmental impact. With the focus on infrastructure, especially on bridges, Rijkswaterstaat is also facing problems, such as the maintenance and replacement of old bridges. Combined with the challenges in the AEC industry, an innovative solution which boosts productivity and sustainability is required. This solution should also include circular management, with consideration of its after-service use. In this project, we developed a digital workflow for bridge(beam) structures with 3D concrete printing technology, to address productivity and sustainability in the design and manufacturing process.

Project Overview

This digital workflow provides a more efficient design process by allowing users to assess the feasibility of the design from the structural and fabricated perspective. It also involves material optimizations or reusability concepts during the design process. This project focus on the development of structural design tools and demountable(dry) connections. The former provides users with real-time structural feedback in the design process which helps to realize material optimization, and the latter helps to create reusable structures from a circularity perspective.

Structural design tool

The structural design tool is developed in the same parametric environment as the digital workflow, based on the design criteria as 1) providing real-time simplified structural indications; 2) providing clear visualization for material use; 3) providing clear visualization for possible prestressing locations. Based on the basic beam theory, the structural calculation is implemented at the cross-sectional level during the design process, through emended Python code. Users can adjust their design according to immediate structural indications. This structural design tool is verified with a series of experimental and numerical validations.

Dry connection design

The dry connection is designed with the focus on interlocking shapes and interlayer material, according to the criteria of mechanical property and manufacturing requirements, as well as sustainability and durability requirements. The dry connection prototype is designed as a sine wave interlocking shape with a cork board interlayer, which is validated with experimental tests.

Conclusion and future expectations

This project delivered the structural design tool embedded in digital workflow, and the design of the dry connection prototype with a circular perspective. This project also disseminated relevant knowledge and information through public presentations and exhibitions. In the future, this digital workflow is expected to cover the design not only for bridge structures but also for infrastructures or buildings, involving more sustainable design concepts and more complex structural feedback.

This project has been established in collaboration with TU/e and Rijkswaterstaat.