The Xypex Fast-Track Coating Method for a “Rapid Return to Service”

The Xypex concrete waterproofing procedure detailed below is intended for
situations when there is too little time available to waterproof structures using
normal Xypex coating application and curing procedures. Typical situations
include structures taken out of service for planned or unplanned maintenance
but where a return-to-service is required within days or even hours. For example,
the Xypex fast-track method was used to waterproof the storm/sanitary sewer
line in Detroit, Michigan where it could only be out of service for two separate
eight-hour periods, spaced 16 hours apart (see photos below). Other examples
include process or holding tanks in chemical or other manufacturing facilities
where a maintenance shutdown is only possible for a few days before
prohibitive financial penalties are incurred.

IMAGE 1 – Inside of pipe pressure-washed in first 8-hour closure. Note the very rough surface with exposed aggregate caused by cement paste loss.

IMAGE 2 – Xypex Concentrate followed by Xypex Megamix I is applied in second 8-hour closure.

Normal Xypex Coating Procedure

Typically, a Xypex coating treatment of existing concrete requires either one or two coats of Xypex Concentrate, or Concentrate  and Modified followed by three days of moist curing. An additional 12 days of drying and hardening prior to water immersion in potable water, or 15 days prior to immersion if the water is waste contaminated, is also required.

Fast-Track Xypex Coating Procedure

The following procedure enables the early opening of the Xypex coating to prolonged water contact within 3 – 4 days from the start of the material applications, thereby allowing a more rapid returns to service.

1. Pressure wash and clean the concrete surface to achieve an open pore, “tooth and suction” profile.
2. Repair joint lines, cracks and surface defects if required as per Xypex standard repair process.
3. Coat the surface with one coat of Xypex Concentrate at 2 lb/sq.yd. (1 kg/m2) as per Xypex standard specifications.
4. Allow coating to set and harden for 12 – 24 hours. During this time, moist-cure the coating as per Xypex product data sheet.
5. Combine Megamix I with Xycrylic Admixture as per product data sheet instructions.
6. Dampen the Concentrate coating (a damp, not saturated surface) and apply one coat of Megamix I over the top of the Xypex Concentrate coating at a thickness of 1/8″ (3 mm) or 11 lb.sq.yd. (5.6 kg/m2) NOTE: the thickness of the top coating can be varied from 1/6″ – 3/8″ (1.5 – 9.5 mm) depending on job conditions and requirements.
7. Allow the Xypex Megamix I to harden and cure for 2 – 3 days. In moist situations, no curing of Xypex Megamix I is required.

NOTE

1. The above time frames are recommended. However, if project requirements are such that these cannot be met, call your Xypex representative.
2. Consult the Xypex Concentrate and Xypex Megamix I product data sheets for detailed information and procedures.