15 March 2001
concrete and the patching material. Curing procedures for PCC must be strictly followed to
prevent shrinkage cracking. Curing shall be by moist curing for at least 7 days followed by
application of white-pigmented membrane-forming curing compound. The curing procedures for
PCC shall be performed as follows:
12.1.1. Commence immediately after finishing is complete for each repair (patch).
12.1.2. Apply two layers of completely presaturated clean burlap conforming to AASHTO M182
12.1.3. Resaturate (oversaturate) the burlap after placing and immediately cover with clear or
white polyethylene sheeting at least 100 micrometers (4 mils) in thickness.
12.1.4. Cover with plywood at least 1/2 inch (12 millimeters) thick or wood form material and
weight down sufficiently to prevent displacement by wind.
12.1.5. All covering materials, burlap, plastic, and wood shall extend at least 6 inches
(150 millimeters) beyond every edge of the patch.
12.1.6. At least once every 24 hours, the plywood and plastic shall be removed, the burlap
resaturated, and the plastic and plywood immediately replaced.
12.1.7. When moist curing operations are complete, remove the plastic sheet and the plywood
between 20:00 and 24:00 hours in the evening. Between 3 and 7 hours later, remove the burlap
and immediately apply a uniform coat of white-pigmented curing compound to the repair area.
Curing compound shall conform to CRD-C300, and shall be applied at a coverage rate 200
square feet per gallon (4.9 square meters per liter).
12.1.8. Patches shall be protected from traffic for at least the following 7 days.