und mechanisches Verhalten des Schaumglases
von Dr. sc. techn. ETH Rudolf Trinkner

Key structural and physical properties of foam glass


Comparing foam glass with traditional insulation materials, its relatively high compressive strength σdB is notable.

At the density of ρ = 0,5 gr/cm3 fine-celled foam glass has the compressive strength σdB=5,6N / mm2 . In comparison for cellular concrete of the same density, this is substantially lower at 2,5 N/mm2 .However disadvantages in terms of brittleness and failure under low tensile and shear loads must be taken into account.

Foam glass is easy to saw, mill, file and drill, and has a low bulk density.

The linear thermal coefficient of expansion of foam glass can be assumed to be on average for the temperature range of 0 to 33°C. In comparison it is (9÷11)⋅10−6 °C−1 for concrete and 8⋅10−6 °C−1 for cellular concrete.

Foam glass is a very poor thermal conductor. Thus for two foam glass test pieces selected at random the density ρ=0.137gr / cm3 and ρ=0.217gr /cm3 and the thermal conductivities of λ=0.055w /m⋅°c and 0.072w /m⋅°c respectively were determined using the single-plate unit.

Cellular concrete of density ρ = 0,5 gr/cm3 has a value of 0.22W / m⋅°c for λ.

On a test piece of foam glass type 1 of density ρ=0.277gr / cm3 a water-vapour permeability of λD=34,8⋅10−5mg / m⋅h⋅Pa was observed. There are

foam glasses of density ρ = 0.137 gr / cm3, which have a significantly lower water-vapour permeability of λD=7,2⋅10−5mg / m⋅h⋅Pa.

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A. The structure of foam glass