Kemko® bonding agents are generally used to join fresh (plastic) concrete to old concrete, hardened concrete to existing concrete and masonry, or to attach other materials including stone to, or embed them in concrete or masonry. On horizontal surfaces and in vertical, downward oriented holes, the liquid form of these adhesives is generally preferred. On walls, ceilings, overhead and horizontally oriented holes and for the repair of wide cracks, pastes (gels) are the preferred products. While concrete to concrete and concrete to steel bonding constitutes the major use for these materials, attaching certain rubbers and plastics to concrete or steel, or steel to steel and wood bonding applications are also significant uses.
Long work life bonding agents are generally desirable in applications requiring significant manual labor and when cure time is not a constraint. Short work life bonders are the preferred materials at low application temperatures and in applications where relatively fast cure times are important. The liquid bonders are often used in structural grouting applications and can be mixed with a variety of aggregates optimized for the specific application.
The long and short work life bonder liquids and pastes are compatible with each other and can be blended to achieve certain application viscosities and potlives. The A and B components of each product should be pre-mixed, proportioned, combined, mixed again and then combined with the other pre-mixed material.
All Kemko® Bonders are formulated for application shortly after mixing, when they have the best substrate wetting and viscosity characteristics. The creamy consistency of the Kemko® Bonder pastes facilitates trowel and caulking gun application. These features aid materially in the achievement of good production rates during application. The excellent physical properties of the Kemko® Bonders allow their use in applications requiring resistance to creep and stress relaxation, maintenance of mechanical properties at high ambient temperatures and high load bearing strength. The excellent substrate wetting and water displacement properties provide high adhesive bond strength, even under adverse application conditions.
Substrate surfaces must be sound, free of standing water and of all bond inhibiting substances (see also Surface Evaluation and Preparation which also comments on hole preparation for dowel grouting). Cleaned concrete should have a minimum strength of 250 psi in direct tension. Steel surfaces should be cleaned to “white metal” according to SSPC SP 5.