An investigation of high performance concrete bridge girders

The objective of this dissertation is the development of parameters related to the analysis, design, and behavior of high performance concrete (HPC) bridge girders in order to facilitate and insure the ability to achieve HPC in a full-size prototype bridge using conventional fabrication techniques and local materials. Specific tasks included a literature review, bridge plan review, development and monitoring of a quality control program for the concrete mix, development of an instrumentation plan, installation of instrumentation, data collection, analyses of data, and development of recommendations. The successful fabrication, erection, and introduction into service life of the HPC bridge girders investigated has shown that HPC bridge girders can be built using local materials and current fabrication techniques.; The instrumentation program was used to monitor concrete curing temperatures, prestressing strand forces, prestress losses, and camber/deflection. In addition, a concrete materials testing program was conducted to measure compressive strength, modulus of rupture, modulus of elasticity, shrinkage, creep, coefficient of thermal expansion, and permeability.; The concrete curing temperature distribution was used along with match-cured and field-cured test cylinders to illustrate the importance of using match-cured cylinders to determine the compressive strength of HPC.; The concrete curing temperatures were also used along with the prestressing forces measured prior to strand detensioning to illustrate the effect of high curing temperatures on prestressing forces. Thermal losses due to the temperature difference in the prestressing strand occurring between the time the strand was tensioned and the time the concrete bonded to the strand represented a significant loss that is not accounted for in current design codes.; The prestressing force, prestress loss, camber/deflection, and material property data was used to examine the ability of current design codes to accurately predict the behavior of HPC bridge girders. These codes proved unable to accurately predict the prestress loss and camber/deflection of HPC bridge girders. As a result, changes were recommended based on a time-step analysis that accurately predicted the behavior of the HPC bridge girders.