SENAD® HLWC is a concept developed in Sweden, designed with modern research techniques. Characteristic of this process is many applications, the high precision and reproducibility of the homogeneous pore structure. This results in a controlled uniform quality and good properties, especially conserning insulation, moisture and strength.


Hardened SENAD® HLWC has very good strength relative to density. We tailor the density of our low-weight product from 400kg/m³ up to 2300kg/m³. The material has good thermal insulation capacity, is fireproof resistant and easy to work with at lower densities.

Cost effectiveness

SENAD® HLWC offers several saving advantages over both traditional concrete and other types of lightweight concrete. The air in the concrete created during the mixing process is no additional cost. The concrete can be produced on site in bulk, in smaller quantities but also in an outside factory, to be transported by truck. The material can be pumped so it ends up exactly where you want it. It is almost self-leveling and requires no compaction.

The air filled concrete can also be used to prefabricate units. This light weight material costs less to deliver. It is easier and cheaper to move these units when arrived at the workplace.

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SENAD® HLWC reaches, according to theory, about half the R-value of conventional insulation. Today’s theory, however, is optimized for mineral wool or foam insulation and therefore does not do full justice to our material. We double the thickness compared to for example foam, which gives a very good insulation effect. Affecting factors include humidity, pore structure and the fact that the material does not have any seams.


SENAD® HLWC neither absorbs moisture from the ground or the surrounding material, which is advantageous for the insulating effect. This means fast access to the site. The design can be laid directly on the ground but the most common method is to add a layer of gravel underneath to give free passage to any water during construction.
For example during flooding, the material does not absorb water to any significant degree. Simply pump the water away and use a dehumidifier for some days and then the floor can be used again. This is a clear advantage for both property owners and insurance companies.


In a fire plain concrete usually explodes due to expansion within the material or when exposed to water. SENAD® HLWC contains a large proportion of air pores which take care of the expansion and therefore does not affect the material, when exposed to heat. Additionally the material stores very little heat, which is an advantage when firefighters go in after a fire. The material does not implode by rapid cooling.

Foundation reinforcement

At cave ins, foundations or foundation slabs, SENAD® HLWC does an excellent job to strengthen the foundation with small means.


Our concrete is laid out by pumping it directly from the mixer. Uncovering and slight leveling of the ground is sufficient. The material can be pumped relatively long distances if required, up to 50 meters.

A final design can involve:

  • gravel at the bottom
  • 200- 300 mm SENAD® HLWC as insulation
  • vapor barrier and the supporting floor
  • 40-70 mm reinforced standard concrete or screed.

If floor heating is required, it should be placed on top of the SENAD layer so that it is cast into the concrete or screed.

A layer of screed on top of the SENAD® HLWC of 15 – 20 mm can be used to increse quality.

Harbor, pier and lock (water transport) restoration

SENAD® HLWC is a concrete mass that penetrates cracks and cavities and has unique features regarding port and lock renovations. SENAD® HLWC is versitile and can easily be adapted to any problem and is a material that does not dissolve in water. The material has low viscosity, high penetration of eroded filling and a good filling capacity in cavities, cracks, etc.

Low Cost Housing

During the years 1996-2004, SENAD® HLWC was used in a low-cost (prefab) project in Asia. India and the Philippines were the countries that were given the opportunity to use our technology concrete and the project was very successful!

For more information, see “More information” >> “Documentation”

Sliplining and renovation of road and trackbed culverts

The main alternative to our method SENAD® HLWC is that you must close off the road, rail or work area, dig up old fillings, remove the material and the old culvert and carry this away. After that you have to add a new culvert and fill with new material. We can fix the culvert without affecting the environment and/or traffic or the material around the existing culvert.

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Benefits by using the SENAD® HLWC method

 activity can be made from one direction
 no traffic needs to be diverted
 large reduction of future cave ins
 increased throughput in and through the culvert
 stabilization of surrounding land area is not needed

Economic benefits

 the work is quick and easily applied
 no transportation costs for moving material, a new culvert or hazardous waste
 no new filling material and no compacting
 sharp reduction in the cost of future cave ins

Tunnel & Crack grouting

SENAD® HLWC has had a good result when used in Hallandsåsen, Ådalsbanan and the Southern Link. The work included crack sealing, rock grouting and sealing against water.

Our method compared to other methods

 with this revolutionary technology, it is now possible to effectively seal cracks and crevices in an environmentally safe way.
 SENAD® HLWC injection penetrates the deepest, finest cracks and crevices. The material effectively seals and closes the smallest crevice.
 the material has no swelling function which is a great advantage when sealing dams. Other options have major risk factors, many of which can worsen the cracking further.
 SENAD® HLWC injection does a perfect “waterproofing job.”


We get a lot of requests about leakage problems. Usuallly it involves groundwater finding its way to the lowest possible pressure points.  To seal this type of leakage has been very costly and not always 100% successful. Furthermore, by using toxic substances to seal it has also created serious risks of groundwater pollution. This problem is eliminated with SENAD® HLWC. The market for this method is enormous because of more underground work is required in towns along roads and railways.

Do you want to know more? Contact us