Evaluation of Methods for Characterizing Air Void Systems in Wisconsin Paving Concrete

Date Started: March 3, 2003

Date Ended: 2006-05-31 00:00:00.0

Budget: $199,965

Sponsor: Wisconsin Department of Transportation

Performing Organization: Michigan Technological University

Description: Properly sized and space-entrained air bubbles protect concrete from cyclic freezing and thawing, yet current methods for evaluating the air entrainment in fresh concrete are complex and difficult to apply consistently. This problem, combined with potential shortcomings in current use of synthetic air entraining admixtures to enhance air void, can together encourage overly high air content and weaker, more permeable and less durable concrete. The objectives of this research are to establish the relationship between measured air content of enhanced fresh concrete and air void system parameters, to develop new methods of assessing air void systems in hardened concrete, and to determine and encourage the best construction and materials selection practices. Tasks entail literature review, analysis of data, preparation of mixtures, testing of fresh concrete, testing of hardened concrete, analysis and final recommendations. The expected benefit of this study is stronger, more durable concrete pavement. Specific benefits will be a better understanding of how admixtures impact air void systems, and improved methods of testing and evaluation fresh and hard concrete for air void characteristics.