Improved sound insulation



Better sound insulation has traditionally been a question of increasing the mass/weight of the construction. With the SL-deck it is possible to make a very sound insulating stucture with a deck thickness of just 22 cm and a weight of 375 kg/m2.


The SL-Decks high level of sound insulation is due to two primary factors:


Combination of materials


effect of internal arches

Ordinary self-compacting concrete and lightweight concrete have different eigenfrequencies. When sound is transmitted, the two types of concrete in the SL-Deck thus vibrate differently. This means that a part of the sound waves are converted to heat instead of passing through the deck. 






In the ancient Rome, arches were very widespread in construction due to their good sound properties among other reasons. Arches are stiffer than a flat plate resulting in higher eigenfrequencies, which is benefical as the most difficult eigenfreqencies to reduce lie in the low end of the spectrum. In the SL-Deck, the self-compacting concrete is constructed as a series of arches over the lightweight blocks and thus contribute to the high level of sound insulation.

SL-Dk lydisolering


Sound test


The SL-deck has undergone accredited sound tests measuring the sound insulation of the SL-Deck to:


Airborne sound insulation: 57 dB

Impact sound penetration: 77 dB.


Watch the sound test of the SL-Deck below:


4 hours fire resistance


With a fire resistance of minimum 4 hours, the SL-Deck is the most fire resistant prefabricated concrete deck. The deck thus fulfulls the strictest requirements without need for fire insulation.


The high fire resistance is due to the deck design, where the prestressed reinforcement is protected by the insulating and fire resistant lightweight concrete. Lightweight concrete mainly consists of LECA (light expanded clay aggregate), which is literally ”born” in fire as it is produced in ovens at app. 1,200 degrees celcius.


Watch the fire resistance of the SL-Deck below:


Fire test



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