Performance-Related Specifications for Concrete Bridge Superstructures, Volume 1: Performance Parameters and Related Procedure for Concrete Bridge Superstructures

In Volume 1 of the final report, the identification of performance levels and parameters, and the development of acceptance criteria, have been addressed. Emphasis has been placed on the development of a methodology for a Performance Related Specification, PRS, for concrete bridge superstructures. The implementation of the methodology, presented in the form of a user-friendly computer program, is project specific. It requires the mean and standard deviation (or definition of a probability distribution) of the input parameters for the performance predictive models. This is done for both the as-designed condition and the as-built condition of the structure. The contractor is expected to achieve certain level of compliance during the construction as dictated by the as-designed condition (which is defined based on the submitted design in compliance with agency specifications). Based on performance predictive models, cost models, and statistical simulation, the methodology reports a ratio of the as-built/as-designed Life-Cycle Cost (LCC). This LCC ratio measures the level of compliance of the asbuilt structure with the design. This approach enables the agency (INDOT) implementing the methodology to consider the LCC ratio in the form of a pay factor modifying the contractor’s bid price. In proposed methodology, statistical simulation is conducted to evaluate the effects of the variations in the input parameters for the performance predictive models. The differences in the LCC for the as-designed and as-built elements come from the differences in the input parameters that are under the control of the contractor (referred to as quality characteristics). The framework of the methodology has been fully developed with the case study of a simply supported reinforced bridge deck or slab. The proposed methodology is further illustrated with four numerical examples. Based on the work in this phase of the research program, it was concluded that the most practical implementation of the methodology considers the corrosion deterioration problem as the only distress determining/affecting the LCC of the structure. It was also concluded that other distress indicators applied at “a section level” can be included in the framework of a PRS to give more integrity to the process of quality control. It must be noted that corrosion deterioration represents almost 50% of the problems in the current bridge infrastructure in Indiana