The LEGO-house in Billund, Denmark is a project, which was started from a LEGO-scale model. The current LEGO bricks are as old as the writer of this blog and are still loved by creative children. The building is based on these interconnected LEGO bricks and as a consequence, a flat roof is chosen.

It was decided to go for passive housing with a large resistance against fire. Mineral wool at a large thicknesses (passive housing) is sensitive to natural convection with low outside temperatures. On the other hand, PIR and other polymer foams were not accepted due to the combustibility.

However, the combination of PIR and GLAPOR cellular glass guarantees a passive housing thermal resistance at moderate thickness without any fire risk and without any risk for internal natural convection. This principle was already suggested a long time ago and recently KINGSPAN and GLAPOR started a collaboration. In the following, several pictures of the installation of the GLAPOR-KINGSPAN system are given.

GLAPOR cellular glass on a Danish cultural symbol under the nose of Rockwool Lapinus, another Danish symbol, “Il faut le faire”, Cellglasplader.

The problems with humidity, diffusing from the soil into the house is already known for a long time. Less known are the problems with radioactive gases like Radon and sulfur dioxide gas in some countries. The picture hereunder shows where sulfur dioxide is emitted by the vulcanic underground (red squares).

Every problem has a solution and the Daliform group came with a good idea. Under the floor, they install cavities, manufactured from plastic, to be able to ventilate these unhealthy gases.

On top of the ventilated space, thermal insulation has to be installed because we do not want to heat the ventilating air with expensive energy.

Although the above solution works, the combination ventilation / thermal insulation can be done with (closed cell) cellular glass. GLAPOR cellular glass is 100% impervious to these and other gases (like ordinary glass) and eliminates the need for a ventilated space. On top of that, it functions of course also as thermal insulation with a high load bearing capacity.

I would be surprised if the combination of the cavities / XPS thermal insulation is not a lot more expensive than GLAPOR cellular glass, installed on the concrete with hot bitumen. And we may expect also a much longer life time with the cellular glass solution, which is also proven to be ecological.

We are used to build on stable terrain and disregard the possibilities of less stable ones. But sometimes, we have not the choice (we don´t make a curve with a railway due to terrain conditions) or we can buy such a land at a very good price. In these cases, we can use geosynthetics to stabilize the terrrain.

With GLAPOR cellular glass gravel, it is advised to use a geotextile to separate the gravel from the soil. Without using this textile, intermixing between gravel and soil will induce a cold bridge into the gravel. In the picture on the right, this textile is called geogrid. In reality, a geotextile is used with the following specifications.

A gravel bed is only loaded in compression or shear and can be described as a cellular structure based on cellular glass. This gravel bed does certainly not behave as a beam, it has no bending strength at all. As a consequence, all the bending strength of the system has to come from a (concrete) plate on top of the gravel.

But today, we have also cellular confinement systems, also known as geocell. The brand name Geocell Schaumglas is also used for foamed glass gravel, but this is clearly not what we mean, when we speak about geocell. The picture on the left shows an old application in Alaska.

This geocell  structure, filled with clay, induces an important extra bearing capacity compared to unreinforced clay like shown in a paper paper. Like can be observed in the graph, the effect is dramatic if geocell and geogrid are used. For a settlement of 20%, we have an increase in bearing pressure of at least a factor 3. This is defined as the load bearing improvement factor.

The (beam) effect is also demonstrated in a paper paper about improved road constructions with geocell reinforcement. Indeed, the geocell helps to distribute the load of a tire over a much larger surface, increasing the life time of the road. In this case, the experiments were done with PRS Neoweb, a geocell based on Neoloy. This polymer is an improvement, compared to HDPE, which is usual used for geocell.

At this moment, we can ask ourselves what we can do with a geocell, filled with GLAPOR cellular glass gravel? At least, the application in the previous post will be improved. Indeed, roads on foamed glass gravel will have a much larger life time. But in a lot of cases, we can construct a lighter structure than with ordinary gravel, thanks to the wedding of cellular glass gravel and geocell. Even for the standard house application, the use of geocell will induce extra stability allowing to reduce the thickness of the concrete slab on top of the foamed glass gravel.

About 24% of the Northern Hemisphere lives with permafrost, which means that the underground remains frozen during at least two years. However, there is always an active layer which thaws in summer. The water is not able to be absorbed by the froozen underground and this induces a swamp unstable underground. The following pictures are a typical example of this unstable underground for buildings and roads.

These instabilities can be solved by using GLAPOR cellular glass gravel like shown in the following schematic drawing. This configuration with about 30 cm gravel avoids that the underground thaws or eliminates the active layer. This system can be used for houses like alreay shown in previous posts but also for roads, like calulated in a paper of the Norwegian government. 

Foamed glass gravel is a light strong material, able to bear the load of a road and insulate the underground from the climate changes. It allows cheaper more stable constructions by recycling waste glass.

I found the following article about a petroleum storage burning with even a movie. Ken Revart writes:

 It appears to me that the the thermal insulation on the spheres begins to char at the equator from radiant heat and then ignites after subsequent explosions. I understand that this facility installed PUR/PIR foam insulation for cold process. I have to wonder how the pipe insulation stood up to the fire. Did the PUR/PIR melt away and contribute to the cascading affect of the explosions.

What are your thoughts or experiences of fire protection from mechanical insulation in these scenarios? (I skipped the last sentence to respect a legal settlement)

With GLAPOR cellular glass, this catastrophe would never happen because cellular glass is non-combustible. It is produced from 99.9% glass without using any binder. In fact, reinforced with a ceramic mesh on the opposite side of the fire, it behaves as a very good fire resistance.