TechBrief

2014PDFTech ReportFHWA-HRT-14-030HRDI-40/02-14(250)ELightweight concreteMild steelUnited StatesTurner-Fairbank Highway Research CenterTurner-Fairbank Highway Research CenterFederal Highway AdministrationConcrete with a unit weight between that of traditional lightweightconcrete (LWC) and normal weight concrete (NWC)is not covered in the American Association of State HighwayTransportation Officials (AASHTO) Load and Resistance FactorDesign (LRFD) Bridge Design Specifications.(1) This researchprogram includes a significant number of bond strength testson this type of concrete. The results from this research projectare included in a database that covers a broader range of unitweights in order to determine trends for LWC as a functionof unit weight. New design expressions for the developmentlength of mild steel in tension are proposed for LWC thatinclude a modification factor for LWC based on unit weight