SENAD®HLWC (Hydrofobic, Light Weight Concrete) invented in a mechanical workshop in the Swedish village of Ånge, at “Danes Verkstäder”. This company has had many internationally recognized patents. After requests from the concrete industry about an environmentally friendly lightweight concrete, they developed SENAD® HLWC together with AkzoNobel. The old type of lightweight concrete contained cement and plastic foams. Samples with the new lightweight concrete started in the 1980s and the material was patented in 1992.
We have a close collaboration with the laboratory and the designer who helped to invent this concrete, this is unique in the sector today. Materials develop, as well as the cement and then we also have to change our recipes for the concrete. The designer and the inventor of SENAD® HLWC has a lab where all the tests are carried out so that the material is always adapted to today’s requirements. The concrete industry can be very conservative and we are often asked to solve late problems, instead of contacting us at an earlier stage. This changes as the product becomes more known.
SENAD® HLWC can be described as a foam concrete which contains air pores. The difference between SENAD® HLWC and ordinary concrete is that ordinary concrete is often mixed with plastic foam instead of supplying bubbles of air. Our product is made on site in special machines with water, cement and surfactants (Surface Active Agent). A surfactant produces foam like a regular detergent, but our bubbles of air are very durable. The otherwise ordinary lightweight concretes are being phased out, because most areas do not allow plastic or other artificial affecting materials pumped into the ground today.
The characteristics of our concrete are: fireproof, insulating, hydrophobic and light. We can mix different densities with ease. To give an example, ordinary concrete has a density of 2300 kg/m³. Our concrete has a density of only 400 kg/m³ when there is 80% air in the concrete. We usually mix a density between 400 kg/m³ to 1000 kg/m³. We can also change the density easily at the location which also makes our product unique.
Our company is the only contractor in the world that utilizes this lightweight
With more air the concrete easily becomes more fire resistant and insulating than regular concrete. The air in the pores work as regular insulation against heat and cold. We use this lighter density for the insulation of the foundation slabs, isolation of old floors and foundation/land stabilization etc. SENAD® HLWC is gas tight and stops smells, radon and other gases. If you have suffered a cave in under a house, it means that the ground has yielded. When this happens, you do not want to add any heavy extra weight as normal concrete does. The cave ins accelerate with heavier weight. SENAD® HLWC does not add extra stress on land or structure.
In this mix we add sand as an aggregate. You lose a bit of water repelling and insulation capabilities. The product remains waterproof.
This mixture we usually use for casting under water and on the sea bed. Our surfactant allows the concrete to cure even under water.