Air Void Analyzer - Factsheet
The Air Void Analyzer (AVA) is a portable device that measures the entrained air void structure of fresh concrete in about 30 minutes. Test results correlate closely with ASTM C-457 values obtained on hardened concrete. The AVA can be used at the job site to make admixture adjustments that can dramatically improve the air void structure and thus the freeze-thaw durability of the concrete.
The AVA can be used to measure the air content, specific surface, and spacing factor of fresh portland cement concrete. Because the new technology can be used on fresh concrete, it allows real-time evaluation, helping to improve quality control.
The Kansas Department of Transportation has been using this technology since April 2001 and has developed a State specification that it uses routinely. Kansas will work with the Federal Highway Administration to lead the TIG implementation effort. Implementation goals include developing a common standard test protocol, specification, and data collection form that all States could use and identifying training needs and available resources.
More details are included in the AVA Introduction Brochure. Operation of the equipment is shown in the Real Air Testing in Real Time video clip below.
Real Air Testing in Real Time, an AVA presentation by John Wojakowski, Kansas DOT Concrete Research Engineer, includes photos of concrete damage, graphs depicting the relation between durability and spacing of bubbles of entrained air, and data comparing the AVA and ASTM C 457 Spacing Factor.
The AVA Data Collection Excel Spreadsheet, compiled by the AASHTO Technology Implementation Group for the Air Void Analyzer (AVA) technology, provides a standard format for data collection and data sharing efforts in evaluating the AVA. The intent of this effort is to collect necessary information from across several laboratories and to help relate one study to another. The worksheets in this file are assigned self-descriptive names that can be associated with the nature of information/ data to be entered in it.
State and Federal Implementation Plans from the Iowa Department of Transportation, a Federal Highway Administration/Iowa State University team, the Virginia Transportation Research Council, and the Missouri Department of Transportation mention research and further testing of the AVA.