As we have sites stretching from Salgesch to Goms, we are able to guarantee short transport routes.
Building materials have to deliver what they promise – this is just as true for special civil engineering as it is for building construction. That is why the Volken Group's internal building materials laboratory in Gamsen puts many building materials through their paces before they are used. "We use scientific methods to, for example, show whether concrete meets the ever higher demands. We determine whether it meets all standards and what can be improved. Whereas concrete in ancient Roman times consisted of water, stones and cement, today it contains much more, such as additives and admixtures," says Tobias Zeiter, who is in charge of internal quality assurance at the company and helps to test selected building materials to see whether they meet the buildings' requirements.
As a customer, our laboratory will be happy to advise you on questions relating to your construction project and prepare expert reports for you. In addition, we also handle special requests, produce delicate concrete systems such as coloured concrete, hard concrete, flowing screed or SCC and further develop RC concrete and RC building materials. Special applications with well-thought-out pumping systems complete our range.
The Volken Group laboratory lorry has all the tools on board to analyse fresh concrete from A-Z. The samples are taken and tested directly on the construction site. Our company is very flexible with this specialist vehicle and can be on site anywhere from Lower to Upper Valais.
To determine how much water is in the concrete, it is boiled – that's to say dried-out. The fresh concrete is weighed, heated until no more water is present and then weighed again. For every type of concrete measurable water loss shows whether the ratio, and thus also the required w/c, ratio are correct.
The air content also provides information about a concrete's quality. To measure it, concrete is placed in the air-entraining pot. The air-entraining pot can additionally be used to determine the bulk density of the desired concrete. If air is missing, it can be added as desired in the form of powder or admixtures.
In order to use concrete, a certain temperature must be guaranteed. If it is too cold, you can either heat the aggregate with hot air or increase the concrete temperature by adding heated water. More effort is needed to cool the concrete. Spraying the aggregate with cold water can lower the temperature in the concrete. Other methods such as adding dry ice are also possible.
Exactly this can be demonstrated with a compression test on specimens. For this purpose, fresh concrete is normally poured into cubes of 150 mm edge-length, stripped of its casing the following day and placed in a water bath at 20 degrees Celsius. On the desired test day, it is placed in the ultra-modern cube compression press. Here, a measuring rod analyses its mass, weight and pressure proportion. The process is fully automatic and the results can be output as a protocol.
Permeability tests of building materials are not only of central importance in hydraulic engineering; it is the only way to determine whether protective dams can withstand a flood – those built by Volken Group along the Raspille, for example. To test permeability, the infiltration rate is determined with the double-ring infiltrometer shown here. Each material has its own values, which is why we test the composition before construction begins and optimise it directly on the construction site if necessary.
In the Volken Group's in-house laboratory, specialised testers of building materials with many years of experience work with the latest technologies. They ensure that all standards are met and – where necessary – improve the properties of building materials, for example fresh and hardened concrete or aggregates and material mixtures.