Chemical Injection 101
The Basics
What is chemical injection?
Chemical injection or chemical grouting is a method to seal, contain, or stop water infiltration and consolidate soils by means of environmentally safe polyurethane foam or sometimes other chemicals.
On this page we'll focus on polyurethane chemical injection, most often simply called grout.
What's in it?
Polyurethane chemical injection consists of the following components
​Isocyanate Component
The isocyanate component is the main building block of the polyurethane polymer. It acts as the cross-linking agent that reacts with the polyol component. The most common isocyanates used in polyurethane grouts are diphenylmethane diisocyanate (MDI) or polymeric isocyanates. This reaction between polyols and isocyanates is known as the "polymerization" process, leading to the formation of a solid, durable polyurethane matrix.
Polyol Component
The polyol component serves as the other main building blocks of the polyurethane polymer. It is a liquid or semi-liquid substance, typically a polyether or polyester polyol. During the reaction, polyols react with isocyanates to form polyurethane polymers. The type and composition of polyols influence the properties of the final grout, such as flexibility, strength, and hardness. It is very important to use a high-quality polyether for maximum stability and durability.
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Blowing Agent
The blowing agent is an optional component used to introduce bubbles or expand the grout during the reaction. This expansion helps to increase the volume of the grout, filling gaps and voids in the application area more effectively. The type and amount of blowing agent influence the grout's density and ability to penetrate and stabilize the substrate.
Catalysts
Catalysts are essential to promote the reaction between the polyol and isocyanate components. They act as initiators, kick-starting the polymerization process. The use of catalysts is crucial to control the reaction speed and ensure the grout cures properly within the desired time frame.
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Surfactants
Surfactants are surface-active agents that help control the foam structure and improve the fluidity of the grout during mixing and injection. They reduce the surface tension between different components, allowing for better mixing and uniform distribution of the grout during application.
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Stabilizers
Stabilizers are used to ensure the stability and shelf life of the polyurethane grout product. They prevent premature reactions between the polyol and isocyanate components, ensuring the product remains effective and doesn't degrade while in storage.
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Colorants
Colorants are optional additives that provide the desired color to the polyurethane grout. This can be useful for visual purposes to differentiate different grout formulations for various applications.
Typical Uses
Applications
ADCOS is a premier chemical Injection grout
ADCOS® manufactures a premier chemical injection grout that has been trusted by many premier contractors on many prominent landmarks and esteemed universities.
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Working closely with our network of waterproofers, engineers and consultants we develop a strategic plan of attack per application. Drilling for ports, injection pumps, activated oakum, expansion joints, injection tubes, needle or stem injection are all in our arsenal to effectively stop your leak.