15 March 2001
monomer; therefore, several monomer applications are necessary. This method usually requires
a higher concentration of monomer than the premixing methods and is generally limited to
monomer systems with viscosities less than 100 cp.
11.4.2. Premix placement. This method is identical to that used for the placement of PCC. The
polymer binder is first added directly to the mixer, then the fine aggregates, and finally the coarse
aggregates. Mixing is continued until all particles and completely wetted. This method can be
used for binders with low or high viscosities with a predetermined quantity of polymer binder.
Depending on the product, consolidation of the PC can be obtained by tamping, vibrating screed,
or small-diameter vibrators. The repair area is usually primed with the polymer binder prior to
placement of the PC patch material.
11.4.3. Prepackaged PC. These systems can be mixed by hand or in mechanical mixers. If a
rotating mixer is used, all of the monomer or resin system should be added to the mixer and
blended first. The powders and fine aggregates are added, followed by the coarse aggregates,
and the entire blend is mixed for the specified time. The entire composite is then placed and
consolidated utilizing the manufacturer's recommendations. Once the PC has been placed by
any one of the described methods, it can be finished by manual or vibrating screeds, or by
manual or power trowels.
11.5. Safety. The chemicals used to produce some PCs may be flammable, volatile, and/or
toxic. The degree of hazard is greater for high-vapor pressure materials.
With proper precautionary measures, these materials can be handled safely. The manufacturers
of the chemicals and the prepackaged systems will provide recommendations for safe storage,
mixing, and handling. Additional safety recommendations are provided in Chapter 5 of ACI