Shear behavior of high strength self-consolidating concrete in NU bridge girders

As the nation\u27s infrastructure continues to age, advanced concrete technologies have been developed to both reduce a structure\u27s costs and increase its life expectancy. Since the early 1990\u27s, self-consolidating concrete (SCC) has been one of these technologies. Many, however, have been reluctant to implement SCC in highway girders due to the mixture constituents. One of these concerns is the reduced content and size of the coarse aggregate. These differences in the concrete potentially hinder SCC\u27s mechanical properties and shear resistance. Additionally, for high strength concretes (HSC) with weaker aggregates, shear cracks tend to propagate through the coarse aggregate, reducing the aggregate interlock component of the shear resistance. This study aimed at assessing the web-shear strength both with and without web reinforcement of two precast-prestressed Nebraska University (NU) 53 girders fabricated with high strength self-consolidating concrete (HS-SCC). The results were compared to the ACI 318 (2011) and AASHTO LRFD (2012) code estimates, and a finite element model (FEM) package, Response 2000. ATENA Engineering, a finite element analysis (FEA) program, was also used to evaluate the qualitative results, specifically crack patterns and the effect of the coarse aggregate content and size. A prestressed concrete database was also constructed to assess the effect of the reduced coarse aggregate content on the shear capacity of HS-SCC in prestressed concrete members. The mechanical properties of the HS-SCC mix were also tested and compared to relevant empirical equations. The HS-SCC mix investigated in this study proves to be a viable cost-saving alternative for bridge superstructure elements --Abstract, page iii