Production to Industry 4.0 standards
The benefits of prefabrication are indisputable – a highly efficient, cheaper and faster manufacturing process and the reduction of traditional sources of error. Read more on this in our interview with Jörg Theves, Factory Manager at the EMC prefabricated components factory near Erfurt.
Mr Theves, prefabrication is a crucial part of the business model at CG Elementum. The job of the EMC factory will be to produce, deliver and assemble the necessary components. As Factory Manager, you are instrumental in driving forward implementation of the upcoming rollout in the main factory. How do things stand?
Handover of our production facility and office building is already complete and the first employees are on-site. The factory will be operational in January 2021 as planned. We will then initially test the performance of the facilities. The first components from this dry run will feed straight into the D17 pilot project at the Plagwitzer Höfe site in Leipzig. This will be the first Gröner Group building constructed using EMC prefabricated concrete components. As of March 2021, the factory will then be all set to produce 1,850 m² per day in single-shift operation.
How will the production process work?
We intend to manufacture prefabricated concrete components to Industry 4.0 standards. The dimensions and requirements for every single one of these units will be provided and processed digitally. Our factory building will cover 16,000 m² and include a state-of-the-art automated carousel production line. Here, steel tables will move from station to station in a fully automated process to manufacture a range of units. First, shuttering robots will position the steel formwork for the components. A reinforcing cage will then be added, in other words the inner framework. At the next station, conduit or cable bundles, sockets and other installations will be fitted by hand. This will then be followed by fully automatic concrete casting. The now concreted unit will then be moved into the curing chamber. This will have space for 82 steel tables, with every table holding up to four units at once. In the curing chamber, the concrete will be cured at an ambient temperature of 35 to 40 degrees. The temperature will be generated through so-called hydration heat without the need for additional heating.
The next morning, the cured units will be moved to the lifting stations, where the prefabricated concrete components will be taken off. The steel table will be cleaned and moved back to the first station with the shuttering robots. All automatically.
Some members of staff will surely be needed?
Compared with other prefab market leaders, we will minimise the number of staff members needed per square metre by a large margin. As a comparison: for the number of prefabricated concrete components manufactured with a daily production of 350 m³, other companies need 45 people loading in a three-shift system. At the EMC factory, we will need just one or, at most, two employees in a single-shift system. Less manual work means fewer sources of error and greater process reliability. We will also only hire in-house personnel under permanent contract. None of the factory work for the production process will be carried out by subcontractors or agency workers.
What kind of production volumes are we talking about? What output will the factory be capable of?
Let’s take the D17 pilot project in Plagwitz in Leipzig. For this we will need to produce 530 ceilings, 635 walls and 64 cavity walls ‒ a concrete surface area totalling around 13,000 m² and encompassing a range of layouts. In single-shift operation we will be able to manage 1,850 m² per day. So for the entire build we will need a mere eight days. As soon as we adopt a three-shift operation, things will move faster. Instead of 400,000 m² per year, we’ll then be able to produce 1.2 million m². In theory, this figure could be much higher if we added extra heating to the curing chamber and/or accelerated the concrete curing process with chemicals.
So the components will then be delivered straight from the factory to the construction site?
Yes, in single-shift operation we will have 35 lorries filled with sand, gravel and cement arriving at the site every day. Just as many will then transport the finished units away to the construction sites. Normally it would be even more, but in conjunction with both of the haulage firms we are working with we have developed our own trailers that can carry 20% more load. This will mean four fewer lorries on the motorway every day. That’s around 880 fewer lorries per year – and this is only with single-shift operation.
Environmental factors are a core consideration for CG Elementum. How do you respond to the fact that concrete production is one of the largest CO2 emitters?
Firstly, we will use a CEM II cement here that has 20% less CO₂ emissions. Secondly, we have a long-term focus on recycling and are already in negotiation with demolition companies. We are in a position where we will be able to use up to 40% recycled material for our components. Environmental considerations have been factored into our plans right from the start.
It is similar to the digital process chain, where we are able to produce highly bespoke designs for our concrete units without losing any time. The same is true here: we don’t want to use production techniques that are state-of-the-art today. We want our production now to already meet the standards that we expect to apply in 10 to 15 years’ time. This foresight is what makes European Modular Constructions GmbH so special. In this spirit, we are now already planning the expansion of our factory.
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