| While the response of structural concrete members to the actions of axial load and bending moment is quite well predicted, the shear behavior is still poorly understood. Consequently, most of shear design code provisions are principally empirical based on a limited number of test data available and vary greatly from code to code. Thus, this thesis aims to improve the understanding of the shear behavior of reinforced concrete members and prestressed concrete members.; With an extensive literature review of studies on shear, failure theories, shear behavioral models, and shear design provisions in national codes of practice, experimental test data have been extracted from previous experimental research and compiled into a shear database (SDB). This database is used for studying parameters that affect shear behavior/strength and for evaluating and comparing six national shear design provisions---ACI 318-02 ; AASHTO LRFD Bridge Design Specifications (2001); CSA A23.3 2004 edition (Collins, 2003); Eurocode EC2, Part 1 (2003); the German Code (DIN, 2001), and Japanese Code (JSCE Standards, 1986)---as well as for identifying research needs.; In the last decades, developments in high-strength concrete materials are rapid, but codes of practice still limits the concrete compressive strength in design of concrete structures due to a lack of experimental research data. As an effort to overcome the limitation to the use of high strength concrete (HSC) in shear design, an experimental study, Project 12-56 "Application of the LRFD Bridge Design Specifications to High-Strength Structural Concrete: Shear Provisions" funded by the National Cooperation Highway Research Program (NCHRP), has been conducted. This dissertation work presents the experimental study on shear behavior of six large prestressed concrete girders cast with HSC. The test parameters of this experimental investigation are concrete strength (10, 14, and 18 ksi), shear stresses (stirrup strengths from 900 to 2300 psi), strand profiles (draped or straight strands, debonding), and end enhancement details. The effects of test parameters on shear behavior are examined including service load level behaviors, and the performance of the aforementioned shear provisions is evaluated with the test results. Recommendations for future research are provided based on findings from this experimental study. |
