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June 21, 2023

Using Pecora Dynatrol II Two-Component Polyurethane Joint Sealant in Horizontal Traffic Applications

Pecora Dynatrol II, two component, low modulus, urethane sealant is a non-sag caulking material designed for sealing expansion joints when excessive movement is expected. The cyclic movement rating on this sealant is +/- 50% in expansion and compression when tested according to ASTM C-719. The non-sag consistency and high movement capability of this sealant make it desirable for horizontal applications in pedestrian or vehicular traffic areas such as parking garages, where a self-leveling sealant can sometimes be problematic due to excessive flow on sloping concrete slabs.

Sealant joints in traffic areas can be subject to severe abuse from contact with automobile tires, environmental debris such as rocks, glass, foot traffic, and standing water. When using lower modulus sealants in traffic applications, the practice of some simple but important guidelines is necessary for a successful project. Check them out below:

Guidelines

  1. Joint Dimensions
    1. Always use proper sealant dimensions with respect to width to depth ratios. The general guideline is 1:1 width to depth in joints up to 5/8 inch wide. And 2:1 thereafter, with a maximum joint depth of ½ inch in joints up to 1 ½ inches wide. In special cases where joints exceed 1 ½ inches in width a 2:1 ratio may be maintained.
    2. Added sealant thickness in wide joints while maintaining a 2:1 width to depth ratio will aid in puncture resistance while maintaining movement capability and long term performance.
  2. Pedestrian Traffic Applications
    1. Sealant joints wider than 5/8” using Dynatrol II for horizontal application with heavy pedestrian access must be capable of resisting puncture. A pedestrian joint design, which has been somewhat successful, consists of semisolid joint filler, such as fiberboard or rigid polystyrene foam, with bond breaker applied to its surface in contact with the sealant. Periodic inspection and maintenance should be a realistic consideration to ensure a consistent waterproof expansion joint. No special backing consideration is necessary when using Dynatrol II in horizontal joints 5/8” or less in width. Minimum joint width for Dynatrol II in horizontal traffic applications is ¼”.
  3. Vehicular Traffic Applications
    1. Dynatrol II may be used in vehicular traffic joints using the same joint dimension guidelines discussed in section “A” above. In areas not to receive pedestrian traffic a semi-rigid backing is not needed, nor is it necessary to recess the sealant within the joint as would be necessary with less abrasion resistant silicone based sealants.

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