Poly-Foam Injection Resin
Product profile summary
Stratathane ST-520 Poly-Foam is a hydrophilic, single component,
flexible polyurethane resin based on TDI for sealing leaks in
concrete and masonry structures. ST-520 Poly-Foam reacts with
water, expands, and then sets into a flexible closed-cell foam.
ST-520 contains about 15% acetone and has a sweet, solvent-like
odor. The acetone lowers viscosity and assists in distributing
the available water through the resin. ST-520 is essentially non-toxic
in its cured form.
is usually injected directly from the can into the leak using
either a single or a plural component pump. ST-520 creates an
elastic seal that stops water entry but allows crack movement
to protect against stress transfer. The cured material exhibits
excellent adhesion to concrete and is not corrosive. At 70 F,
reaction time is approximately 30 seconds and cure time about
two minutes. It has no preset Apot life@ and does not cure as
long as water or moisture vapor are not available to start the
two-stage reaction takes place when ST-520 comes in contact with
water. The mixture first expands and thickens. Then, as it cures,
ST-520 quickly solidifies into a strong impermeable water barrier
in just minutes. Unrestrained ST-520 foam expands up to ten times
its starting volume. However, a dense material is preferred for
most applications. Greater density is obtained by controlling
grout placed relative to void space and static head pressure.
ST-520 is rated high in its ability to tolerate freeze-thaw, wet-dry
cycling, extrusion, and compression.