DSM SYSTEM Installation in Concrete

DSM SYSTEM Installation into Concrete Expansion Joints

On this project we are replacing a failed inflated-type expansion joint seal. This older technology relies on adhesive that is in severe tension during the joint opening cycle. It is prone to adhesive failure.

The deck is a factory-topped, precast double-tee syst

The DSM SYSTEM consists of:
– 6.56 LF (2m) sticks of the precompressed foam (in long brown boxes);
– 2-part epoxy adhesive (yellow boxes);
– sausages of silicone (white labeled boxes).
The DSM material expands slower when cold and faster when hot.

On this cool, early autumn day, the material was stored in the sun to warm it up to make it expand a bit faster.

(On hot days, the material would be installed in the shade, in an air-conditioned van or room, or can even have bags of ice placed on top of the sticks in the boxes if needed to slow expansion).

With the old, failed joint system removed and the deck surface along each edge masked with duct tape, the EMSEAL-supplied epoxy is applied to joint faces.

The glove method is a rapid-production alternative to using a margin trowel.

Meanwhile another crew member opens a stick of DSM by cutting on the hardboard packing to release the shrink-wrap.

The first stick is eased into the joint opening leaving the end to be joined sitting out above the deck surface.

Using a sausage gun and the sausages of silicone shipped with the DSM SYSTEM, silicone is applied across the silicone bellows face on the end of the stick.

By lowering the bottom of the stick into the joint, it is checked for fit.

If not snug enough to hold its own weight, the material is left alongside the joint to expand a bit further.

While this is happening another stick, or sticks, can be opened and laid on the deck alongside where it will be installed.

When expanded enough to support its weight, the stick is inserted and the join made. The rest of the stick is pushed firmly towards the join. This motion actually compresses the stick lengthwise further ensuring a tight join.

The middle portion of the stick is eased down to its finished height just below the deck surface. Note that the join is still proud of the deck.

Finally, the join is pressed into the joint to the finished height. This final compression of the join ensures that it is in compression and a tight fit.

Excess silicone that squeezes out of the join is tooled away to ensure that the bellows is not constrained.

Silicone sealant bands are injected between the bellows, foam and concrete. The excess silicone that squeezes out is tooled into a corner bead.

Duct-tape masking is removed.

Installation is complete…

…and in service the next day…

..taking SUV traffic…

…car and pedestrian traffic…

…and ideal for deck-to-wall conditions.