Quality Function Deployment Based Method for Condition Assessment of Concrete Bridges

Bridge condition assessment is essential step in bridge management. To ensure safety and serviceability of bridge infrastructure, accurate condition rating methods are needed to provide basis for bridge Maintenance, Repair and Replacement (MR&R) decisions. In Canada and the United States, visual inspection and close-up observation are the common practice to detect surface defects and external flaws. Non-Destructive Testing (NDT) and evaluation technologies are used during visual inspection to reveal subsurface defects. It is paramount to develop systematic methods to capture inspection data and to produce robust condition rating and MR&R decisions. The current research reviews current practice in bridge condition assessment and discusses the main deteriorations and defects identified during visual inspection and NDT and evaluation. Further, the research discusses limitations of available bridge condition assessment models and introduces the Quality Function Deployment (QFD) theory as a novel approach to the area of bridge management. The principles of the QFD theory are demonstrated with a real case study and the potential of using the approach in the area of bridge condition assessment is discussed. Different defects correlations are measured based on an expert’s opinion and are included in the developed QFD method. Wasserman’s normalization technique is embedded in the method to take into account interdependency between the different defects. The QFD method recommendations are compared to other condition assessment methods and validated against twenty bridge projects which were assessed by bridge inspection teams. The validation showed consistent results between inspection teams’ assessments and the QFD method recommendations.