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Every year, incomplete concrete repairs and insufficient corrosion protection cost building owners throughout the United States considerable money and time. A simple, yet often overlooked, "fifth step" of concrete repair has proven successful worldwide in ensuring the integrity and durability of concrete repairs — while significantly lowering overall lifecycle costs.

It is estimated there is more than 9 billion cu. yds. of "in-place" concrete in the United States, most of which is more than 20 years old. The use of concrete in construction has continued to grow rapidly, from approximately 220 million cu. yds. in 1990 to 400 million cu. yds. in 2004. This significant quantity of concrete and strong growth rate of concrete use in construction translates into a U.S. repair market of more than $18 billion (USD) per year.

Consult an engineer

These statistics indicate that the typical repair involving deteriorated concrete and corrosion of reinforcing rebar will become more frequent. Before defining a specific repair method, it is necessary to consult an engineer with the appropriate expertise for an assessment of the key dynamics behind the deteriorating concrete. The engineer examines the extent of structural damage, along with a determination of the cause, in order to design a material repair system that will ensure integrity and durability of the structure.

There remains, however, a lack of a solid understanding within the concrete industry as to the best method to address concrete deterioration. Some currently used repair methods — whether topically applied or introduced into repair materials — have yielded inconsistent results and compromised repair performance. This ultimately results in loss of time, money and credibility for both contractor and engineer, while the building owner ends up with disappointment, frustration and no return on dollars spent.

Factors affecting deterioration of concrete

The dynamics behind concrete deterioration are important to understand as effective repair solutions are considered. Virtually all concrete has at least small micro-cracks. These minute cracks, combined with the natural porosity of concrete, open an avenue for chloride (carried by moisture) to penetrate into the concrete, eventually reaching the rebar. As the rebar corrodes, it expands, "blowing" off the cover of concrete, and accelerating the cycle of deterioration.