ST-538 Bed-Rok Injection Resin

ST-538 Product profile summary
Stratathane ST-538 Bed-Rok Soil Stabilizer is a low viscosity MDI-based injection resin for structural repair, water control and soil stabilization applications. ST-538 reacts very quickly with ST-539 in a 1:1 ratio to form a dense, very hard solid.
Stratathane ST-538 is mixed with ST-539 at the work site to form a single injection material. A twin-stream pump is preferred but the material can be bucket-mixed and batch-poured in small quantities for surface gravity feed applications. The inert end product forms a water barrier which is essentially unaffected by acids, gasses, and micro organisms usually found in soil. The product is water-tolerant, and clean dry surfaces are not required for successful applications. Even large amounts of water can be accommodated through displacement.

ST-538 is useful for a wide range of water control and soil stabilization applications, including water-bearing soils and sealing cracks or joints in concrete and terrazzo walls, buildings, dams and utility vaults, especially in applications requiring high strength.

ST-538 may be placed by hand pumps or multi-ratio power pumps. Stainless steel pipe and fittings are recommended but not strictly required because ST-538 is no more corrosive than water. Cleanup of solidified material in the system, however, may sometimes be accomplished with caustic cleaning compounds, making stainless steel advisable.

The very low viscosity of ST-538 Bed-Rok makes it easy to inject. Once cured, its impermeability makes it an effective water shut-off system. The permeability of soil grouted with ST-538 depends on how well its voids are filled with grout. Values in the 10-7 cm/sec range should be obtained using ASTM Constant Head Permeability Test Method D-2434.

Set time is the period from first contact of ST-538 with ST-539 to the point where the mix becomes too thick for gravity flow. The set time is influenced primarily by the mix temperature. Custom formulation is available for set times ranging from about 30 seconds up to about 10 minutes. Set times are longest at low temperatures and vary a little with the age of the resin. The viscosity of mixed ST-538 is lowest for the first 80% of the set time and increases rapidly as the mix approaches set.

At 78EF Stratathane ST-538/ST-539 solidifies in about one minute. When injected into soils, the set time is increased to as much as ten minutes. Cooler temperatures slow down set time. Warmer temperatures accelerate the set time.