FAQ (Definitions)
Website Definitions:
- Ambient temperature: The surrounding air temperature as opposed to the temperature of a surface or element.
- Efflorescence: A crystalline deposit of salts that form when moisture is present in brick, stone, stucco or concrete. It has a white greyish color and consists of salt deposits that remain after the moisture has evaporated.
- Surface seal: The material, normally an epoxy paste, applied over a crack to contain a resin as it is injected and until it cures.
- Centipoise: The unit of measure for viscosity. The thicker the material, the greater the centipoise.
- Cold joint: A joint formed when a concrete surface hardens before fresh concrete is placed next to it. It is characterized by poor bond unless special procedures are utilized.
- Core: A cylinder of concrete removed from an element, usually for the purpose of inspection and/or testing. For epoxy injection applications, a 2-inch diameter core is typical.
- CPS: Abbreviation for centipoise.
- Crack: A physical break in concrete. Can be caused by shrinkage, thermal movement, impact, loading or other stresses.
- Dispenser: A device incorporating one or more pumps for pressurizing and delivering resins. Usually at a predetermined rate of flow and/or pressure. For two component materials, the flow rates of the pumps are synchronized to dispense the components at the required ratio.
- Dwell: The amount of time a catalyzed resin is curing in the dispense lines beyond the mixer and prior to entering the crack.
- Fault: A crack, fissure or other linear defect found in concrete.
- Hydro: Pertaining to water.
- Laitance: A layer of weak, nondurable material containing cement and fines, brought to the surface of overly wet concrete by the water bleeding to the surface.
- LPL: Abbreviation for long pot life. A common industry designation for an epoxy with a longer than normal pot life.
- Lubricity: The slipperiness of a material.
- Manifold injection: The process of injecting numerous ports at once.
- Micro-fissure: A separation in concrete, such as a crack, which is so narrow and shallow that is is rarely of concern.
- Modulus: An engineering property that expresses the rigidity of a material. The higher the modulus, the stiffer the material.
- Port: An entry point where resin is injected into a crack or void.
- Porting: The procedure of establishing ports.
- Porting adapter: A device used to facilitate the connection from a resin dispensing source to a void in concrete. It may be applied to the surface so as to span the crack of inserted into a hole drilled into the crack.
- Pot life: The time is takes for a resin to gel after mixing as determined by the test method described in ASTM C 881.
- PSF: Abbreviation for pounds per square foot.
- PSI: Abbreviation for pounds per square inch.
- PU: Abbreviation for polyurethane.
- Seam: A linear flaw in concrete that is not a crack. Such as a cold joint.
- Spall: A concrete fragment not normally restrained by internal reinforcement.
- Static mixer: A mixing device with no moving parts in contrast to a dynamic mixer that utilizes rotating blades.
- Viscosity: The thickness of a fluid, or a fluids internal frictional resistance to force that tends to cause it to flow. High viscosity materials, such as gels and pastes are relatively thick and tend to resist flow. Low viscosity materials are thin liquids, like water, which flow easily.
- Wetting ability: The capacity of a resin to enter the pores of concrete and develop a physical bond.
- Working life: Amount of time available to apply a resin after mixing before is begins to gel.
- Yawning: The opening and closing at the surface of a crack due to thermal changes.