Comparison of conventional and internally cured concrete bridge decks in Utah : Mountain View corridor project.

PDFTech ReportUT-15.022513570Concrete curingConcrete bridgesBridge decksFine aggregatesMoisture contentCrackingCompressive strengthPermeabilityModulus of elasticityField testsLaboratory testsUtahUtah. Dept. of TransportationGuthrie, W. SpencerYaede, Joseph M.Bitnoff, Amanda C.Brigham Young University. Dept. of Civil and Environmental EngineeringUnited States. Federal Highway AdministrationUS Transportation CollectionThe objectives of this research were to 1) monitor in-situ moisture and diffusivity for both conventional concreteand concrete containing pre-wetted lightweight fine aggregate (LWFA), 2) compare deck performance in terms ofearly-age cracking, compressive strength, and chloride ingress, and 3) compare concrete properties in terms ofcompressive strength, chloride permeability, elastic modulus, and water content in the laboratory using cylinderscast in the field at the time of deck construction. The research involved field and laboratory evaluations of fournewly constructed bridge decks located in northern Utah, two constructed using conventional concrete and twoconstructed using pre-wetted LWFA to promote internal curing. Data from sensors embedded in the concrete decksindicate that the volumetric moisture content and electrical conductivity of the internally cured concrete were higherthan those of the conventional concrete during the 2-year monitoring period. Laboratory data indicate that theinternally cured concrete was weaker at 1 year following deck construction, passed less current in rapid chloridepermeability testing, had a lower modulus in free-free resonant testing, and had a higher gravimetric moisturecontent than the conventional concrete. In the field, the internally cured concrete was weaker at 2 years in Schmidtrebound hammer testing and exhibited greater chloride concentrations at both 1 and 2 years than the conventionalconcrete. The conventional concrete bridge decks had more reflection cracking from the joints between theunderlying pre-cast half-deck panels than the internally cured concrete decks