Concrete pavement mixture design and analysis (MDA) : assessment of air void system requirements for durable concrete.

PDFTech ReportPart of InTrans Project 09-353Part of DTFH61-06-H-00011 Work Plan 25Concrete pavementsAdmixturesMix designSpecificationsFrost damageAir voidsFreeze thaw durabilityAir entraining agentsUnited StatesIowa State University. Institute for TransportationLey, TylerFelice, RobertFreeman, John MichaelIowa State University. National Concrete Pavement Technology CenterUnited States. Federal Highway AdministrationNTL-HIGHWAY/ROAD TRANSPORTATION-Pavement Management and PerformanceNTL-HIGHWAY/ROAD TRANSPORTATION-DesignUS Transportation CollectionConcrete will suffer frost damage when saturated and subjected to freezing temperatures. Frost-durable concrete can be produced if aspecialized surfactant, also known as an air-entraining admixture (AEA), is added during mixing to stabilize microscopic air voids.Small and well-dispersed air voids are critical to produce frost-resistant concrete.Work completed by Klieger in 1952 found the minimum volume of air required to consistently ensure frost durability in a concretemixture subjected to rapid freezing and thawing cycles. He suggested that frost durability was provided if 18 percent air was created inthe paste. This is the basis of current practice despite the tests being conducted on materials that are no longer available using tests thatare different from those in use today.Based on the data presented, it was found that a minimum air content of 3.5 percent in the concrete and 11.0 percent in the paste shouldyield concrete durable in the ASTM C 666 with modern AEAs and low or no lignosulfonate water reducers (WRs). Limited datasuggests that mixtures with a higher dosage of lignosulfonate will need about 1 percent more air in the concrete or 3 percent more air inthe paste for the materials and procedures used. A spacing factor of 0.008 in. was still found to be necessary to provide frost durabilityfor the mixtures investigated