The first step in a successful repair job is to determine the type of concrete deterioration being rectified. If the deterioration is of a continuing nature, investigate the practicality of eliminating the causative factors. For example, can water eroding a concrete surface be channeled in some other direction, or can further corrosive spillage be prevented or heavy traffic on a floor be diverted? If so, the job is to create a patch that will equal or exceed the quality of the original material and, if needed, match the appearance of the surrounding concrete.
Should it be impossible or impractical to eliminate the conditions that have damaged the concrete, there are three choices: Tear out the concrete and replace it with concrete suited to the exposure; increase its strength (for example, by stressing) if it is structurally inadequate; or protect the concrete (for example, by coating, jacketing or resurfacing) if it is the exposure that is causing the deterioration. This article covers the basic repair techniques and materials most frequently used in concrete restoration. If the project is major, it is advisable to consult an expert a consultant, engineer or contractor.
Repair techniques included are: acid etching, caulking, coating, conventional replacement plastic and dry pack; grinding or grooving; injection; jacketing; prepacked concrete; resurfacing thin, regular, bonded or unbonded; shotcreting; stitching; and stressing. Repair materials covered are: acids; bentonite; bituminous coatings; concrete, mortar or grout; dry pack; elastomeric sealants; epoxies; expanding mortars, grouts and concretes; fast-setting materials; fibrous concrete; floor hardeners; jacketing materials; latexes; linseed oil; polymers; silicones; and special cements.