Investigation of the Performance and Benefits of Lightweight SCC Prestressed Concrete Bridge Girders and SCC Materials

11507402009Performing Organization Report No CEE-SG-0662-01PDFTech ReportFHWA-SC-09-02SPR 662High performance concreteLightweight concretePrestressed concreteSelf compacting concreteGirder bridgesConcrete bridgesPrestressed concrete bridgesSouth CarolinaSouth Carolina. Dept. of Transportation. Office of Materials and ResearchRizos, DimitrisCaicedo, Juan M.Barrios, FranciscoHoward, Robert B.Colmorgan, Alexander S.Ziehl, Paul Henry, 1965-University of South Carolina. Dept. of Civil & Environmental EngineeringSouth Carolina. Dept. of TransportationUnited States. Federal Highway AdministrationUS Transportation CollectionSelf-Consolidating Concrete (SCC), also known as self-compacting concrete, is a highly flowable concrete that is capable of filling formwork without using conventional vibration techniques while maintaining its cohesiveness. Currently SCC is used in many commercial applications and is gaining acceptance from many state DOTs for use in precast prestressed bridge girders. SCC is advantageous for many reasons including: (i) the number of workers required and the noise produced by mechanical vibration is reduced significantly; (ii) the safety hazards of workers on top of the girders is eliminated; (iii) the surface finish of the concrete can be more smooth than that of conventional concrete; (iv) formwork damage from mechanical vibration is reduced, increasing the life of the forms; (v) reinforcing bar configurations are not damaged; (vi) improved bond of concrete to prestressed strands could reduce strand end-slip and the top bar effect; and (vii) SCC is able to fill complicated shapes and congested reinforcement areas better than vibrated concrete. This research report addresses the design and resulting properties of normal weight mix designs that were developed at the University of South Carolina and the testing of full-scale lightweight concrete AASHTO Type III girders. Both aspects address material testing for properties in the fresh and hardened states. Fresh properties include slump spread, filling ability, passing ability, and air content. Hardened properties include compressive strength, modulus of elasticity, creep, shrinkage, chloride permeability, and freeze-thaw durability. Testing of the girders includes transfer length, end-slip, midspan deflections, midspan strains, and internal curing temperatures. Summaries and conclusions are provided along with recommended guidelines for implementation.75