Glossary

Black bars: Uncoated plain carbon and low-alloy steel bars for concrete reinforcement that meet the requirements of AASHTO M 31/ASTM A615.

Chromium-alloyed steel bars: Bars with chromium content of less than 16%, such as those meeting the requirements of ASTM A1035 (including proprietary products such as ChromX, formerly marketed as MMFX). Although bars with chromium content of 16% or greater are also alloyed with chromium, these are defined as stainless steel bars.

Common use: A subset of typical use that also includes frequent use.

Corrosion resistance: A quantitative metric or combination of metrics for describing the durability of metallic components against the formation of iron oxides. Examples include chloride concentration threshold for corrosion initiation, time to corrosion initiation, and corrosion rate; these may be related to or independent from one another.

Durability: A quantitative or qualitative description of the long-term performance of a component. Examples include corrosion resistance metrics, time to concrete cracking, time from cracking initiation to a severity of cracking that requires repairs, and other material degradation effects resulting from environmental exposures.

Epoxy-coated steel bars: Steel bars that meet the requirements of AASHTO M 31 with epoxy coatings that meet the requirements of ASTM A775 or similar.

Fiber-reinforced polymer (FRP) bars: Bars composed of fibers (including carbon, glass, basalt, and others) in a polymer matrix, including but not limited to those that meet the specifications of ASTM D8505.

Galvanized steel bars: Steel reinforcing bars with protective zinc coatings that are applied by immersing the bars into a molten bath of zinc (e.g., hot-dip galvanizing that meets the requirements of ASTM A767), applied through the process of uninterrupted passage of long lengths of bars through a molten bath of zinc or zinc alloy (e.g., continuous hot-dip galvanizing that meets the requirements of ASTM A1094) or similar.

Metallic bars: Category representing all forms of CRRBs composed of any type of steel; this represents all forms of CRRBs identified herein with the exception of FRP bars.

Mixed bars: The use of more than one type of reinforcing bar within the same structural member. For example, a top mat of deck reinforcing that is made up of CRRBs and a bottom mat that is made up of black bars; this has resulted in inferior results in past practice.

Qualitative information: In the context of the survey included as part of this synthesis, this refers to performance data that cannot be readily quantified. Examples of this include but are not limited to visual observations, photographic evidence, and experiences of personnel (e.g., state

maintenance engineers or inspectors). For findings resulting from the experiences of personnel to have the appropriate value, it is imperative that such qualitative information be based on collective experience within the state DOT that is informed by factual information and is free from bias and opinions.

Quantitative information: In the context of the survey conducted as part of this synthesis, this refers to performance data that can be quantified. Examples of this include but are not limited to condition ratings, measurements of defects (e.g., crack lengths), service lives, or monetary values.

Splash zone: The portion of a structure that is intermittently directly exposed to water with high concentrations of chlorides. These include natural sources of saltwater as well as water with dissolved deicing agents. Bridge members that can be exposed to water with dissolved deicing agents include bridge decks, superstructure and substructure elements of highway overpasses that are in proximity to the underpassing roadway, and superstructure or substructure elements that may be exposed to chlorides because they are located beneath leaking expansion joints.

Stainless steel bars: Uncoated stainless steel bars that meet the requirements of AASHTO M 334 (those that have a minimum chromium content of 16%) and other products with equivalent chromium content.

Stainless steel clad bars: Steel bars with stainless steel cladding that meet the requirements of AASHTO M 329 or similar.

Steel bars with multilayer coatings: Steel reinforcing bars with coatings of more than one layer, such as galvanized steel with epoxy coatings.

Typical use: Representative of normal practice that may occur frequently (see definition of common use) or infrequently.