Persons faced with choosing one of the many rapid-setting patching materials must decide where, when and how to use which product. They must try to provide permanent patches with the least possible lane downtime, at the least hazard to motorists and workers and at the least possible cost. Whatever the patch material, however, correct preparation of the area to be patched is of first importance. Any impact tool used to remove old concrete tends to leave a damaged layer as it chips away the deteriorated material. Often when a patch fails it is because it has not remained bonded and has pulled away a thin layer of concrete chips, although the patching material remains intact within itself. This may be due either to a shattered interface or perhaps to the fact that the deteriorated concrete was not completely removed before the patch was placed. Water-blasting patch preparation has the potential to eliminate dust, noise and reinforcing steel damage and to reduce or eliminate the problem of shattered interface.
This article provides a synthesis of experience and test results for six categories of materials. These are: Portland cement (Type III, Type III with admixtures, and regulated-set cement); other chemical-setting cements (high alumina cements and magnesia-phosphate); thermosetting resins (epoxy and polyester); thermoplastics; calcium sulfate; and bituminous materials.
Considered against more conventional materials, the fast-setting patching materials appear to offer borderline advantages in particular situations. Although material cost is a small part of the total cost of patching, most of the newer materials do not always seem to offer adequate return for their higher cost, compared with the performance of Type III Portland cement concrete with carefully chosen admixtures.