Installation Guide For Epoxy Grout
Preparation of Concrete Substrate:
The concrete substrate to be grouted must be free of grease, oils, laitance, debris, carbonation and other contamination. A sound, bone dry substrate is required. Roughen concrete substrate to expose large amounts of coarse aggregate.
Preparation of Baseplates and Sole Plates:
The baseplate\sole plate to be grouted should be sanded or sandblasted to a white or bright metal condition. It has been found that sandblasting produces the best profile for epoxy bonding. All oil, grease, paint, and other contamination must be removed. To assure rusting does not occur, it is best that the sanding or sandblasting be preformed no earlier than 24 hours before grouting. The surface to be grouted against must remain free of moisture at all times
Forming for Epoxy Grout Placement:
Epoxy grouts require more physical effort to place than cementitious grouts. The formwork must be very rigid. All forming must be made watertight by sealing all seams and joints with a caulking or sealing compound.
The formwork must be protected from the adhesive power of the epoxy grout. Two methods that have proved successful are: (1) placing polyethylene sheets between the formwork and the grout and (2) coating the forms with paste wax. If the wax method is used, two coats of paste wax should be applied and polished. A third coat should be applied and not polished. This is to allow a surplus of wax at the surface of the form that is to come into contact with the epoxy grout.
Cold Weather Grouting:
At temperatures below 15°C (60°F) the viscosity of the epoxy binder can be very thick, making for a very stiff grout. In this temperature range, the working and curing time will be extended. The strength gain will be slower than at 20°C (70°F). In periods of cold weather it may be necessary to pre-warm the epoxy grout components, baseplate/sole plate, and the foundation. The resin and hardener, while still in their containers, may be warmed by storing in a warm protected room or by immersing in warm water (water temperature not greater than 40°C (100°F). The temperature of the resin and hardener should not be allowed to rise above 30°C (85°F). The aggregate should be stored in a warm area for at least 24 hours, allowing the aggregate to achieve a temperature as close to 20°C (70°F) as possible. The baseplate/sole plate and foundation at the time of grouting should be brought to a temperature between10°C (50°F) and 20°C (70°F). This may be achieved by warming with electrical heating blankets or by tenting the area and heating, using infrared heaters or dry, forced air, free of petroleum pollutants.
Hot Weather Grouting:
As the grout temperature approaches 30°C (85°F) the working time of the grout will be approximately one half of the working time at 20°C (70°F). At 30°C (85°F) and above, placement may become very difficult and steps to control the temperature of the grout and its immediate environment will become necessary. The baseplate\sole plate and foundation should be shaded from sunlight to bring the base plate and foundation temperature as close to 20°C (70°F) as possible. The aggregate should be placed in a cool, dry environment for at least 24 hours. The unmixed unopened cans of epoxy resin and hardener may have their temperature lowered by being placed in a tub of ice water. In very hot weather it may become necessary to schedule grout placement for the coolest part of the day or night.
Premixing the Resin and Hardener:
Epoxy grout is a three component product: resin, hardener, and aggregate. It is essential that the resin and hardener be first mixed separate from the aggregate. The mix ratio of the resin and hardener is a very precise relationship. If the unmixed resin and hardener are mixed in the presence of the aggregate it is very likely that a portion of either component could become lost in the aggregate and never react, thereby resulting in loss of workability and strength.
In order to obtain maximum performance from the product, with the mixer in operation, first place the resin, then pour the hardener (catalyst) into the mixing vessel holding the resin and mix. Carefully inspect all empty resin and hardener containers for residue to ensure that the mix ratio of resin and hardener is in balance. The resin and hardener should be mixed together for at least 2 minutes before adding the aggregate component. A one-half inch variable speed, reversible electric drill, fitted with a jiffy type mixer, is best for this operation. The speed and direction of rotation of the electric drill must be adjusted to avoid the entrapment of air during the mixing operation. The electric drill's direction of rotation must be set such that the mixing action produces a vortex that pulls the liquid up from the bottom of the container to the top. A downward flowing vortex will entrap air. If air is entrapped in the epoxy after the grout has been placed, the entrapped air will migrate to the underside of the baseplate\sole plate and collect as foam. The presence of foam will greatly reduce the load carrying capability of the epoxy grout pad.
NOTE: All equipment being used to mix the epoxy hardener and resin should be cleaned every hour. If this procedure is not followed, flash set may occur.
Adding Aggregate to the Liquid Epoxy Binder:
First Batch - Special Instructions: During the first batch some of the epoxy binder will be lost in coating the inside of the mixing vessel. It is a good practice to reduce the aggregate content of the first batch. The amount of aggregate reduction will depend on the size of the batch and the size of the mixing vessel. This aggregate reduction of the first batch will accommodate the coating requirements of the mixing vessel and provide a good volume balance between the epoxy binder and the aggregate, while maintaining good working and placing characteristics.
Adjusting Placement Consistency:
Adjusting the volume ratio of the aggregate component to liquid epoxy controls the flow of epoxy grout. By reducing the aggregate component as a percentage of the total volume, flow is increased. A moderate reduction of aggregate, up to 25% depending upon manufacturer, will aid in placement and is generally allowed. Note: The reduction of aggregate component volume will reduce the in-place grout volume by a proportional amount.
Mixing Large Batches:
Place the pre-mixed epoxy binder into the tub of the mortar mixer. With the mortar mixer running slowly add the aggregate. Care should be taken not to overload the mixer with too much aggregate at once, to the point of stalling. After all the aggregate is in, continue mixing for 3 to 5 minutes until all the aggregate is uniformly coated with the epoxy binder.
Mixing Small Batches:
Place all the pre-mixed epoxy binder into a pail or tub. With the mixing equipment (electric drill fitted with a jiffy type mixer) in operation, add the aggregate slowly into the tub or pail. The mixing operation must be continual until the aggregate is uniformly coated with the epoxy binder. This operation should take 3 to 5 minutes. During the mixing operation it may be necessary from time to time to push the dry aggregate at the top midway down into the pail or tub.
Caution: All the ingredients in each unit of epoxy grout are precisely proportioned. Any variation from these set proportions can produce grout of poor quality. Broken or partial units of epoxy grout components should not be used. Only materials found in the manufacturers pre-packaged unit may be mixed into the epoxy grout. No other additives are allowed.
Check all formwork, concrete substrate, baseplates / sole plates for compliance with the requirements of this guide. Have all scheduled equipment, materials, and personnel present at the location to be grouted to ensure a continual production and placement of grout on a timely basis. Take temperature readings to ensure compliance with requirements. Grout all holes, bolt holes, and anchor sleeves first. Then begin grouting from one end of the formwork and continue until the entire void is filled - do not place from opposite side. Grouting from two directions should be avoided, as this method will entrap air and create undesirable air voids under the plate. The careful use of banding straps may be employed to move the grout into confined areas. Over-vibrating or excessive strapping must be avoided.
Storage and Handling of Epoxy Grout Components:
All epoxy grout components should be stored in weather tight buildings or warehouses. It is mandatory that the resin and hardener be maintained in a temperature range between 10°C (50°F) and 30°C (85°F). If the resin temperature reaches 4°C (40°F) or below, crystallization may occur. If crystallization occurs the resin will be insoluble in the presence of the hardener and the components will not properly chemically react to form a hardened mass. If this crystallization is apparent, the resin must first be heated to 70°C (160°F) by indirect heat (placing the resin in its container in hot water) and stirred until the crystals dissolve. The resin must be allowed to cool to normal grouting temperature range before mixing with the hardener.
The aggregate component must remain completely dry from the point of manufacture to the time of mixing with the liquid premixed epoxy binder. If the aggregate component is allowed to become wet (or damp), the presence of moisture will create foam in the epoxy binder, which will in turn produce many thousands of small, undesirable voids at the inter-face of the baseplate and the epoxy grout.
A very economical and efficient method for cleaning equipment uses both solvent and abrasive aggregate. The solvent will soften and dissolve the epoxy while the aggregate acts to extend the solvent and, with abrasive action, will mechanically clean, the surfaces coated with epoxy residue.
Mortar mixers can be cleaned by placing about 25 kg (55 lbs.) of dry concrete sand mixed with pea gravel or pea stone and a small amount of aromatic solvent, such as xylol or lacquer thinner, into the mixer and mixing for 3 to 5 minutes. After discharging this mixture, a solution of soap, water and grit should be used, followed by a clean water rinse. Jiffy mixers and other equipment may be cleaned using the same technique.
Note: Cleaning between batches is not recommended unless there is a long delay. Do not add solvent to epoxy grout mixture.
For a reprint of this guide Fax 1-800-954-6314 or print this page.