Experimental Study on the Behvior of High-Strength and Normal-Strength Concrete Beams in a Tennessee Bridge

Abstract

This paper presents an experimental study on a high-performance concrete (HPC) bridge in Tennessee. The bridge is a twin-bridge with high-strength concrete (HSC) beams in one bridge lane and normal-strength concrete (NSC) beams in the other lane. The compressive strength of HPC and NSC were 89 MPa and 48 MPa, respectively. The bridge was instrumented for concrete strains and temperature of precast beams, cast-in-place decks and diaphragms. The cambers of prestressed beams were also measured during various construction stages. Test results presented in the paper include material properties of concretes, temperature changes in concrete, time-dependent strains of precast HSC and NSC beams, cambers of HSC and NSC beams, and strain changes of deck and diaphragm. A comparison study was conducted for the performance differences between the HSC and NSC bridge members. It was observed that the HSC members exhibited rapidly developed early-age creep and shrinkage strains, rapidly developed time-dependent cambers, and obvious differential shrinkage with deck concrete compared to the NSC members. The recommendations for design and construction of HSC bridges are also presented in the paper.