Robot-assisted prefabricated concrete manufacturing could cut environmental impact

At the Digital Concrete 2024 conference, held in Munich, Germany, from 4 to 6 September, a research team introduced a new approach to designing and producing concrete building elements. Their method combines automated design optimization with robot-assisted production to increase the efficiency of concrete prefabrication, with the aim of reducing material waste and environmental impact.

Concrete’s Widespread Use and Environmental Cost

Reinforced concrete remains a mainstay in global construction, due to its strength, ease of use, and cost. However, the production of cement – crucial for concrete – contributes over 4% of the world’s CO2 emissions. While concrete itself can be an efficient choice for load-bearing structures, its large-scale use, especially in wealthier nations, often prioritises quick construction over material efficiency. This leads to designs that are larger and less optimised, simply to reduce labour costs.

This new method seeks to rethink how concrete is used by taking a broader view of its lifecycle – from design and production to reuse – to reduce its overall environmental burden. Instead of focusing on single aspects, the process looks at how each stage can be optimised.

Watch the wrap-up of the Digital Concrete 2024 conference.

Automated Design and Robot-Assisted Production in Focus

The research centred on three main components: architectural design, structural optimisation, and robot-assisted manufacturing. A key feature is a design process that reduces material use by cutting out unnecessary parts of concrete elements. The designs are then fed directly into a robotic production system, ensuring that what is created can be produced with minimal waste.

The design uses an automated structural optimization process with a strut-and-tie model to minimise material use by eliminating non-load-bearing elements.

A novel part of this process is the use of modular robot-assisted production units. These modular production islands are designed to work individually or in groups, both offsite and onsite, making them adaptable to different construction scenarios. They also use a reusable shuttering system, which allows for the efficient production of various shapes in concrete components. The system is operated by six-axis robots that place the elements in position and secure them with magnets during the concrete curing process.

Environmental Impact of Reusing Concrete Elements

The study compared three construction methods: building from new materials, using 100% recycled aggregates, and reusing prefabricated concrete elements. The reuse of existing elements showed the most promise, reducing the global warming potential by up to 75%. In comparison, using recycled aggregates made only a small difference, as the cement content remained the largest contributor to emissions.

The researchers’ focus on reuse means incorporating existing concrete elements into new builds, using modular connections to fit them seamlessly. This not only extends the life of concrete components but also cuts down on the need for new materials.

Smarter Production for a Changing Industry

The robot-assisted production islands may offer a more flexible way to handle complex concrete elements, allowing for the simultaneous production of multiple parts. Unlike traditional production lines, these modular units can process different components at the same time, increasing overall efficiency. The researchers believe that expanding the use of these islands could help the construction sector adopt more advanced production methods, aligned with Industry 4.0 technologies.

By introducing these changes into existing systems, the construction industry could start to reduce its reliance on traditional, resource-heavy methods, moving towards a more sustainable and efficient manufacture of prefabricated concrete elements.

Find the automated design and robot-assisted production of concrete building elements HERE

See: Digital Concrete 2024