ARC Grout Technical Manual

Introduction

• ARC is a water solution of acrylate resins. With the addition of catalysts, a cohesive gel is formed. The set time of this gel may be closely controlled from a few seconds to several hours even in flowing water.
  Because the behavior of the materials can be closely controlled under leak flow conditions, ARC Chemical Grout is ideal for sealing leaks in sewer pipe joints, manholes ,and other structures. It also performs equally well when used to control water seepage in soil and rock or cracks and joints in subgrade concrete structures.
  The ARC grout solution has approximately the similar viscosity to water (3-5 centipoise). Pumped into cracks or soil voids, it produces, after a controlled setting time, an elastic and cohesive gel which stops flowing water.
  

Presentation

The ARC grouting solution is composed of:

• ARC-A
  
• ARC-B
  
• Gel initiator - CAT-TA (Added into ARC-A before use)
  

ARC

• Appearance: slightly viscous clear aqueous solution
• Density:
  - ARC-A above 1.10 g/cm³ at 20°C
  - ARC-B above 1.01 g/cm³ at 20°C
  
• pH :
  - ARC-A above 11
  - ARC-B above 1.5
  

CAT-TA

• Appearance: viscous liquid
  
• Density: above 1.10 g/cm3 at 20°C
  
• Solubility: complete in water

Packaging/Storage

ARC-A / ARC-B

• Sold and shipped in 20L plastic barrels. and/or 200L drum

CAT-TA

• Sold and shipped in 20L plastic barrels
  

Storage

• The shelf life of ARC is 6 months minimum, when stored at temperatures from 5°C to 30°C.
  Catalyst TA may be stored in the original unopened container for at least one year.

Formulation of Grout Solutions

General Grout Formulation

• Grouting solutions are ordinarily prepared by mixing ARC-A with ARC-B in the ratio of 1:1 by volume..
  

Example)
ARC-A 100 L (mixed with additional 1~3% of CAT-TA by weight)
ARC-B 100 L

Viscosity Control

• ARC grout is characterized by its low viscosity (3 to 5 centipoise) which remains constant until gelation occurs. Therefore, ARC grout can be injected until gelation occurs in fine cracks or honeycombed concrete until gelation occurs.
  

Gel Time Variables

• The gel time is the period between the mixing of the two primary solutions(A and B) together and gelation of the final solution. When gelation occurs, the viscosity of the grout instantly increases to yield a cohesive, transparent gel.
  Gel time of the ARC grout can be controlled by changing the catalyst amount. CAT TA is the additive which exert the primary influence on gel time. If long gel time is needed (especially when working with high temperatures) sufficient Potassium Ferricyanide (KFe) must also be added.
  The gel time of ARC grout can also be significantly influenced by the grout temperature, the pH of the grout solution, and the amount of oxygen dissolved in the grout solution.
  In addition, gel time can be influenced by contact with certain metals, by exposure to ultraviolet rays from sunlight, or by the presence of certain mineral salts in the water used to make the grout solution.
  The gel time obtained from a given mix should be determined in the field. Tests of gel time under ambient conditions using water which will be mixed with the grout are recommended.
  

Influence of Temperature

• Gel time for any given catalyst ratio will increase as the temperature of the grout solution decreases, and will decrease as the temperature of the solution increases. As a rough rule of thumb, gel time is reduced by half if the temperature of the grout solution rises 5.5°C.
  

Influence of pH

• In general, as the pH of the grout solution drops, gel time will increase.
  However, with most water supplies, the grout pH is buffered between 8 and 9 when using Catalyst TA. As a practical matter, the use of highly alkaline or acidic water will significantly influence the gel time. Under such conditions, gel time becomes erratic.
  

Presence of Entrained Oxygen in the Solution

• Oxygen entrained and dissolved during vigorous mixing of the solutions will increase gel time.
  

Contact with Particular Metals

• Metals such as iron and copper have an unpredictable effect on the set time of the ARC. The use of plastic or stainless steel tanks is recommended for mixing the grout solutions.
  

Very Short Gel Times

• Gel times from a few seconds up to 1 minute can be obtained by using high ratio of CAT-TA.
  

Gel Properties

Appearance

• ARC gel is elastic and transparent.

Solubility

• The gel produced by ARC is not soluble in water, solvents or hydrocarbons.

Swelling and Shrinkage

• The gel may swell in water up to 200% of initial volume if unconfined. Swelling pressures are small, however, caution should be used if excess pressure is a concern.
  Conversely, placement with exposure to dry conditions for an extended period, may cause shrinkage. Swelling will reoccur if exposed to conditions of high humidity or if reimmersed in water; however, fractures formed during drying will not heal.
  

Permanence/Stability

• ARC gel is resistant to attack by fungi, alkali, diluted acids, salts and gases which are normally present in soils, rock or concrete structures.
  

Compressive Strength (homogel)

• about 0.6 kg/cm²

ARC Gel Properties

Precautions

ARC should be used only by specialists with proper training and equipment.

Handling of ARC

• Prevent contact of the product with skin. Spills on the skin should be washed immediately with water. Additional information is located on the label and the Material Safety Data Sheet.
  Empty drums should not be re-used for any purpose and should be buried in an approved landfill.

Handling of the Catalysts

• CAT-TA is not particularly dangerous but must not be ingested.

Handling of ARC Grout Solutions

• Prevent the contact of the grouting solutions with skin or clothing. Should such contact occur, the skin should be washed with water and clothing changed.

Protective Equipment

• Operators injecting ARC solution should wear waterproof trousers and coats, protective eye glasses, and rubber boots and gloves. Running water for washing should be available.
  

Toxicity

• The single dose oral LD50 of ARC grout for mouses has been shown by unpublished internal studies to be approximately 6,000 mg/kg of body weight.
  ARC gel, when properly catalyzed, produces a gel which is essentially nontoxic.
  

Chemical Resistance of ARC Gels

Gel continuously immersed in the chemical solution not over one year.