19 June 2001
CR-7: REPAIR USING POLYMER CONCRETE
Problem: Concrete roof deck spalling due to corrosion of reinforcing steel and
cracks around support columns.
Description of Repairs: Patch spalled areas with PCC mortar. Coat roof deck.
Reseal joints with polyurethane joint sealer. Requires conventional hand and
power tools. May not be suitable for vehicle traffic areas.
Materials: Take careful measures to minimize drying shrinkage by selecting a
material mix design with a maximum allowable shortage of 0.05 percent and
a. Latex modified portland cement.
b. Polyurethane joint sealant that meets ASTM C 920, Standard
Specification for Elastomeric Joint Sealant.
a. Remove all unsound concrete in the spalled areas. Expose
reinforcing steel all around.
b. Clean the exposed reinforcing steel and entire deck area by
c. Thoroughly clean areas to receive new material immediately prior
a. Patch spalled areas with Latex Modified Cconcrete.
b. Seal entire deck area with neat polyester resin.
c. Remove all joint sealant and reseal joints.
Limitations: The corrosion processes will continue to cause cracks and