Approaches and potentials of circular automated construction

The construction industry is in a dilema. On the one hand, construction must be brought into harmony with planetary boundaries; on the other hand, it is the responsibility of the construction industry to ensure an intact infrastructure and provide adequate living conditions. Currently, these two points are in conflict. The constantly growing demand for new raw materials, energy, and ~ 40% of global waste produced by the construction industry places a significant burden on the environment and greatly contributes to human-caused climate change. The European Union has set itself the goal, within the framework of the European Green Deal, of fundamentally transforming the economy. The current linear economy (“Take-Make-Dispose”) is to be converted into a circular-based model (“circular economy”) to align Europe with the goals of the Paris Climate Agreement and also to promote Europe’s raw material sovereignty. Construction is one of the most significant transformation sectors in this regard. This transformation requires a radical rethinking of the construction industry. On the one hand, it is necessary to extend the life cycles of the existing building stock; on the other hand, the material flows must be redesigned. Thus, buildings that have been approved for demolition must be identified and used as a source for secondary concrete building parts. Due to the high personnel effort involved in these activities, new and efficient machines and digital models must be developed. Automation, which refers to a system/machine that can (semi-)automatically execute certain processes, has already found broad acceptance in other sectors, but it is only slowly being adopted. Yet automation promises to take over dangerous tasks in the complex construction-site environment and to handle repetitive tasks. This thesis presents three developed processes, each assigned to a specific area of potential for the circular economy in construction. The aim of the thesis was to demonstrate the feasibility of automation in circular construction using the example of the following newly developed processes:1. Automation for the Building Refurbishment: The heating and cooling of the building stock in Europe is responsible for 32% of energy consumption. One reason for this is insufficient thermal renovation and a large renovation backlog, caused among other things by a shortage of skilled workers. To counter this, the first robotic façade platform for scaffold-free thermal renovation of buildings was developed. It was shown that, with the help of controlled active and passive compliance, a high assembly tolerance can be maintained. 2. Controlled (De-)Construction and Reuse of Concrete Building Parts: Currently, the recovery of concrete components for circular use is a challenge due to the high manual labor involved. To show how automation can improve existing methods, a robotic process was developed that represents a time saving of 83\% compared to the existing process. Furthermore, it was examined how the existing process can be mapped using a semantic process model.3. Automation in Material Tracking: Not only will the circular construction industry change the way materials are recovered on construction sites, it is also assumed that a decentralized logistics system will develop to collect materials from various construction sites. To enable seamless tracking of materials on construction sites, this work shows how Radio Frequency Identification (RFID) can help to accurately identify components on a crane and track their transport across the construction site.