ST-540 Injection Resin

ST-540 Product profile summary
Stratathane ST-540 is one part of a plural component urethane resin system for sealing cracks in concrete and brick structure. ST-540 mixes with ST-541 to form a dense flexible solid in the leak path. The set time of the mixture can be controlled by ST-542 accelerator and ST-544 is available as a filler. ST-540 has outstanding resistance to water. It has a low liquid-state viscosity. The cured product is physiologically harmless and may be used under controlled conditions in contact with potable water. Stratathane ST-540/541 is a two component urethane resin used for elastic sealing of cracks in concrete and brick structures. ST-540 mixes with ST-541 (the "B" isocyanate component) to form a dense flexible solid in the leak path. The set time of the mixture can be controlled by use of ST- 542 accelerator. ST-544 is available as a filler.

Stratathane ST-540 is the name for a very elastic polyurethane resin from Strata Tech which is used for sealing leaking cracks and expansion joints in concrete structures and for controlling the movement of water through soil and rock fissures. Stratathane ST-540 resin is ideal for sealing wet or moving cracks in concrete because their elastic properties help to avoid further cracks. Stratathane resins are indicated for use when water cutoff is the main objective, cracks move often, and a rigid seal is undesirable.

The elastic Stratathane seal allows a structure to move at the existing crack to help control formation of new cracks caused by shifting stress. This flexible control of stress-transfer means that concrete repaired with Stratathane will normally not crack again. The seal also protects reinforcing bars from water, salts, gases and other oxidizers.

Stratathane ST-540 can be placed with both small and large pumps, from grease guns and simple hand pumps to high capacity, air powered, multi-ratio units. Stratathane ST-540 has been used to repair large and small cracks and expansion joints in buildings, dams, tunnels, utility vaults, electrical conduits, and sewers. Stratathane ST-540 resin seals are not affected by water in the cracks and cavities to be repaired as long as proper application procedures are observed.

The ST-540 resin system itself is solvent and filler free and has outstanding resistance to water. It's low liquid-state viscosity makes it easy to place. The cured product is physiologically harmless and may be used under controlled conditions for crack injection in contact with potable water. The elastic seal created by ST-540/541 allows a structure to move at the existing crack, thereby eliminating additional cracks caused by shifting stresses. The seal also protects reinforcing steel from contact with water, salts, gases and other oxidizers.

ST-542 Accelerator may be added to the mixture when an adjustment of set time is necessary. Field experience, will determine appropriate set time for particular applications. ST-542 must always be added to ST-540 before mixing with ST-541.

After curing, ST-540/541 demonstrates excellent adhesion to concrete and can withstand considerable movement. Water pressure will not affect the cured resin at heads usually encountered in repair work. Cavities and cracks which contain flowing water are handled by adjustment of the set time.

ST-540 has been used to repair cracks and expansion joints in buildings, tunnels, subgrade structures and storm and sanitary sewers. Quantities required for a given repair may vary and will usually be determined by field tests.

The mix ratio is two parts by volume of ST-540 and one part by volume of ST-541. Clean sand may be added as a filler (depending an the application) from two parts up to as much as eight parts of sand to one part of ST-540.
For a specific determination of resistance to an anticipated chemical exposure, a testing program is required. However, the following resistance table for urethane in general may give an indication of the chemical resistance behavior.

ST-540 resin is not resistant to acetone, alcohol, benzene or toluene chlorinated solvents.

POTABLE WATER CONTACT

Air cured samples of ST-540/541 have been tested by a major hygiene institute for possible effects on the quality of potable water. A discussion of the report is available on request..