FAQ’s

WHAT IS A HYDROPHILIC RESIN ? 

HYDROPHILIC POLYURETHANES SHOULD ALWAYS BE USED TO STOP WATER LEAKS IN CRACKS ! Hydrophilic resins seek out water in a crack. They chase the water and absorb into the tight micro-cracks and pores of the concrete. This gives hydrophilic resins a tenacious bond to the wet concrete. Hydrophobic resins repel water in a crack. They resist movement towards wet areas and will not absorb into tight micro cracks and pores in the concrete. They may be forced in under pressure, but the water will act as a bond breaker between the polyurethane foam and the concrete resulting in extremely low bond strengths.

WHY IS BOND IMPORTANT ?

Concrete expands and contracts with changes in temperature. In the summer temperatures rise, concrete expands, and cracks tighten up. In the winter when temperatures fall, concrete contracts, and cracks open up. Polyurethane foams are designed to seal leaking cracks. If the material does not bond to wet concrete, it is destined to eventually fail during these thermal cycles, particularly during cold weather. The cracks will open up and leave a gap between the concrete and the foam allowing water to seep back through.

BUT I HAVE USED HYDROPHOBIC MATERIALS BEFORE AND THEY STOPPED THE WATER !

There is no doubt that hydrophobic resins can be effective at stopping water leaks. They will expand and fill up a wet crack as well as most hydrophilic resins. The failure will usually occur a few months after the job is finished.

DO HYDROPHILIC RESINS SHRINK IN THE ABSENCE OF WATER ?

Some hydrophilic resins will absorb as much water as they come in contact with during the time of initial cure. These resins do a good job of stopping the water leaks, but usually fail if the water table drops. The water they absorbed will evaporate and cause the material to shrink, sometimes resulting in failure. Prime -Flex 900 XLV is designed specifically to eliminate this problem. Prime Resins hydrophilic resins will only absorb as much water as they need to facilitate the reaction during initial cure. The rest of the water is rejected in the same way that hydrophobic resins reject water.

IF PRIME-FLEX 900XLV REJECTS EXTRA WATER DURING INITIAL CURE, HOW CAN IT BOND TO WET CONCRETE ?

Initial cure and final cure are two separate issues. The initial cure is the time when the polyurethane resin foams up. The final cure may take up to 24 hours. It is during this time that hydrophilic resins bite into the pores and micro cracks of concrete.

WHAT IS A HYDROPHOBIC RESIN ? 

RIGID HYDROPHOBIC RESINS SHOULD BE USED FOR STABILIZING SOIL AND FILLING VOIDS! Hydrophobic Polyurethane is usually used to fill voids and stabilize soil because of its low viscosity, high expansion rate, and ability to set up under wet conditions without diluting.

HYDROPHOBIC RESINS REPEL WATER !

When injected into loose soil or voids, it expands and displaces any water present. This rigid hydrophobic-soil stabilization material expands up to 1000% in soil and forms a strong, impermeable mass.

HYDROPHILIC RESIN ABSORBS WATER !

Hydrophilic soil stabilization material absorbs as much water as it comes into contact with during initial cure. This absorption allows the resin to be extended with water. The end result is a gelatin type product that doesn’t add much strength, but is impermeable to water. When the water table drops, moisture in the hydrophilic stabilization product evaporates and the product shrinks. Our testing has shown that re-absorption recovery only ranges from 60-80%.

Because rigid hydrophobic material is not affected by fluctuation in the moisture content of soil, it is virtually unaffected by water table level. It retains its strength, size, and impermeability under almost all soil conditions.

Prime-Flex 910 is an extremely low viscosity rigid foam that will penetrate the finest soils. The set time can be adjusted from over one hour for slow penetration to 30 seconds for penetration rapid enough to cut off underground streams.

Prime-Flex 920 will expand up to 2,000% to fill voids behind tunnel liners, manholes, under concrete slabs, etc., and the set time can be controlled using an accelerator. Prime-Flex 920 viscosity is low enough to be used for soil stabilization.

WHAT IS SOIL BINDING/SOIL STABILIZATION ?

Soil Binding or Soil Stabilization as some people refer to it is a process of injecting a 1-part polymer based liquid to firm up and strengthen weak and/or shifting soils in order to gain superior strength necessary to eliminate erosion or to allow higher load bearing capacity.

Weak or eroding soils will eventually undermine a structure’s foundation or worse, allow it to breach and possibly break and separate.

Precision Chemical Grout uses a Soil Binder comprised of a 1-part polymer that is activated by moisture and not a 2-part polymer/catalyst blend. This eliminates batch-mixing, typically done on-site that can cause differentials during the injection process. The product is created for Durability, Consistency and Predictable strength. In fact, this product has shown to raise typical ball-bearing fill sand to a load bearing capacity of 1200+ psi.

Totally Hydrophobic, the Soil Binder displaces and vacates water during injection. Even swamp-like soil conditions can be bonded to provide load bearing, structural strength and it cures to 90% load capacity in 24 hours.

If you are looking for extreme soil strength, look no further. This product can be injected to depths of 40 feet to strengthen even the weakest soils.

WHAT ARE THE BENEFITS OF “ZERO EXCAVATION SOIL STABILIZATION” ?

For example, road settlement is often caused by leaking underground utilities. The eroded soils caused by these leaks create voids and can quickly reduce the load-bearing capacity of the soils and cause roadway failure. Using Polyurethane Injection techniques we can rapidly repair settlement, leaks and fill all voids in one step. And the best thing is, NO Excavation and very little or NO disruption to traffic. This process can greatly extend the life of your utilities.