28 January 2021 - kl. 12:00

Concrete elements must stay warm

Casting concrete elements is an advanced technological and chemical process that needs to be controlled down to the smallest detail in order to achieve the right quality. Gandrup Element A/S excels at this technique and has optimised the curing process in collaboration with Combitherm

When the North Jutland manufacturer of concrete elements, Gandrup Element A/S, produces elements, it is extremely important that the concrete hardens in the right way. When the concrete element leaves the mould, it needs to harden and the hardening process causes the element to generate heat. However, if the element cools down too quickly, if e.g. it is moved directly out into the winter cold, then things go wrong and the element may not achieve the required strength and cracks may occur in its surface. Therefore, the element must be allowed to harden and cool down properly. This is ensured by controlling the cooling and, thus, the hardening process to allow the element to achieve the right quality and strength.

Insulating mats
Therefore, Gandrup Element A/S has joined forces with the company Combitherm. Combitherm has the right solution which is a specially developed insulating mat that is placed over the element; temperature sensors are placed underneath it, and sensors are moulded into the element. The mat prevents the temperature from decreasing faster than intended, even if the element is placed outside. “So far, we have acquired three mats of this type and our experience with them has actually been good because the mats are easy to handle and ensure that the temperature is controlled. We can easily see this from our continuous measurements,” says Peter Lundquist, Quality Manager at Gandrup Element A/S. He adds that he can see from the measurements that the core temperature of the element and the surface temperature underneath the mat are concomitant which means that the element hardens and cools at the right pace.

It works
And he is supported by his colleague, Ernst Enevold Nielsen, Production Manager at the large factory: “Combitherm actually came up with the idea to try their products. And we actually did experience a bit of trouble with the old mats which were then in use because they were heavy and difficult to handle. Not so anymore. These mats fit in size and are adapted to our needs, and they work fine. The important thing for us is that we can maintain the right quality in the concrete element and that it is not too difficult to handle, ”he says.

A turnkey contractor
Gandrup Element A/S is located in the town of Gandrup just north of the fjord Limfjorden and employs around 120 people. The company is a turnkey supplier of shell structures. With its more than 45 years of experience and active development, the company has gained expertise with all types of concrete and lightweight concrete elements - regardless of the size or special design of a project. A turnkey project may be e.g. a complete pre-assembled shell structure consisting of everything from basement to roof - including facade elements, wall and sandwich elements, decks, balconies, stairs, columns, beams, etc.

Photo: Here, Ernst Enevold Nielsen, Production Manager, covers an element that is to harden with a Combitherm mat. Photo: Torben Sigh