Concrete Repair With Mastic

Mastic is a type of asphalt that is composed of asphaltic cement, limestone and other aggregates and held together with binders. It may be solid or semi-solid, and can be heated and then spread by hand or mechanical means when repairing concrete.

Surface

Generally speaking, surfaces to which mastic can be applied must be true, even and free from irregularities. The surface of concrete to be repaired with mastic should not vary in height by more than about 1/5 of an inch over a distance of 10 feet.

Thickness

Concrete repair mastic applied to high foot traffic areas should be formulated with an appropriate level of thickness. It is typically applied in quantities no more than 2 inches deep to avoid splitting up, or segregation, of the aggregates.

Moisture

If the concrete to be repaired is likely to be exposed to moisture--such as in a toilet or shower compartment, or in a wet process area in a factory--the mastic should be applied in two coats. The first coat in this example should be an underlay or waterproofing mastic.

References

• Mastic Asphalt Council: General Information Index
• Technology Transfer Program: Innovations and Successes of Hot Applied Mastic Patching Materials for Asphalt and Portland Cement Concrete Pavements