Surface Preparation
Proper surface preparation is essential to achieve full bond strength, load transfer, and long-term performance when using SikaFlow 648 epoxy grout for industrial equipment grouting. Begin by ensuring the concrete foundation has reached its design strength and is fully cured and dry. Follow guidelines outlined in ACI 351.1R – Grouting Between Foundations and Bases for Support of Equipment and Machinery, which is the industry standard for grouting procedures.
The surface to be grouted must be clean, structurally sound, and free from dust, oil, grease, curing compounds, laitance, and loose materials. Mechanically roughen the surface to a Concrete Surface Profile (CSP) of 5–9 in accordance with ICRI Technical Guideline No. 310.2 to ensure optimal mechanical adhesion. Avoid the use of bushing hammers, as they can compromise the integrity of the substrate.
Chamfer the edges of the concrete at a 45-degree angle to a width of approximately 2 inches (51 mm). This helps reduce thermal cracking and promotes uniform grout flow beneath baseplates and equipment.
For applications involving anchor bolt sleeves, ensure that all water is completely removed using a siphon, vacuum pump, or rubber hose and bulb. Any remaining moisture should be eliminated through forced air or evaporation. Anchor bolt holes should be sealed using felt, foam rubber, or equivalent materials to prevent grout leakage.
Cover all shims and leveling screws with putty or non-hardening clay to prevent grout adhesion during placement. Use modeling clay, glazing putty, or similar materials. Shim and jack pockets can be formed using wood and filled with damp sand to maintain stability during installation. After the grout has cured, remove any shims or jack screws to relieve stress concentrations.
Finally, shade the foundation from direct sunlight for at least 24 hours before and 48 hours after grouting to minimize rapid temperature changes, which can affect the curing and long-term durability of the epoxy grout.
This detailed surface preparation ensures maximum adhesion, proper load transfer, and reliable performance of SikaFlow 648 in critical applications such as pump foundations, sole plates, turbine bases, and other heavy equipment installations.
Mixing
Proper mixing of SikaFlow 648 epoxy grout is critical for achieving consistent flowability, full aggregate wet-out, and optimal performance in high-strength industrial grouting applications. Prior to mixing, ensure that the aggregate is completely dry to prevent moisture-related curing issues or air entrapment during application.
All components — Part A (resin), Part B (hardener), and Part C (aggregate) — should be preconditioned to 70°F (21°C) for at least 24 hours to achieve uniform temperature and optimal handling characteristics. Begin by pouring the hardener (Part B) into the container of resin (Part A). Stir thoroughly by hand using a spatula or paint stir stick until the mixture becomes a consistent amber color with no visible streaks. This ensures full blending of the epoxy components prior to aggregate addition.
Immediately transfer the mixed liquid into a horizontal shaft mortar mixer or Kol-type mixer. With the mixer running, gradually add the aggregate (Part C) one bag at a time, allowing each bag to fully blend before adding the next. Mix only until all aggregate is fully wetted out — overmixing can introduce air and reduce flow performance.
For the first batch, expect slightly reduced flow due to resin adherence to the mixer walls. To offset this, it is recommended to withhold ½ to 1 bag of aggregate from the first batch of a full unit. This adjustment helps maintain proper resin-to-aggregate ratio. Always add aggregate after the premixed resin and hardener have been combined and poured into the mixer.
Application
Proper placement of SikaFlow 648 epoxy grout is essential for achieving full bearing contact, optimal load transfer, and long-term structural performance in industrial grouting applications. Before placement begins, plan for a continuous and uninterrupted pour. Ensure that adequate manpower, tools, and pre-measured materials are ready to maintain a smooth workflow from mixing through installation.
To facilitate flow across large baseplates or under long equipment skids, metal strapping or rods can be placed in the formwork to assist with grout movement and help eliminate air pockets. In situations where the grout must travel long distances under the baseplate, begin with a slightly more fluid batch of epoxy grout to lubricate the flow path and prevent blockages from occurring in subsequent pours.
SikaFlow 648 should be poured from one side only in a continuous operation to prevent air entrapment and ensure full encapsulation of the equipment base. A consistent hydrostatic head — ideally maintained at a minimum of 15 cm — will help sustain flow and pressure beneath the plate.
Maintain proper clearances during installation: allow 10 cm of space between the form and the baseplate on the pour side, and 5 to 10 cm on the opposite side, to accommodate grout expansion and reduce risk of flow restriction. Be mindful of temperature differentials between grout under the baseplate and exposed shoulders, which can cause debonding or cracking. Whenever possible, avoid exposed grout shoulders; if they are necessary, anchor them firmly with rebar or reinforcement to the foundation to prevent separation.
Ensure the epoxy grout fills the entire void under the equipment and maintains contact with the underside of the baseplate throughout the pour. Do not use mechanical vibrators to place SikaFlow 648.
