Development of an expert system for reinforced concrete bridge repair.

Current techniques for selecting reinforced concrete repair materials are often based on ad-hoc methods for specifying repair material properties. The inherent lack of understanding of material behaviour in this approach can lead to premature failure of repairs.This research has examined state of the art methods for repair material property specification and has developed a technique, specifically for application in a computer program, which recommends optimum repair material properties tailored to given repair situations. The technique developed achieves compatibility between the repair material and the substrate concrete through a sophisticated balancing of those repair material properties identified as important, specifically; elastic modulus, shrinkage, creep and tensile strength. Adopting the developed technique minimises the possibility of failure of the repair material.The developed repair material property selection technique is seamlessly integrated into an expert system for reinforced concrete bridge repair also developed as part of this research. A technique has been produced to quickly elicit the complex decision making process of reinforced concrete experts and represent their information in a computer program.The developed expert system diagnoses the causes of reinforced concrete defects. Importantly, the program utilises its in-built intelligence to determine if the severity and extent of the defects identified warrant genuine concern.In order to facilitate efficient inputting of data into the expert system by prospective users, an elemental graphical interface was developed, allowing users to quickly assemble onscreen three dimensional representations of the affected concrete elements. Thereafter, program users locate areas of defects onto the on-screen concrete elements and the inputted data can be interrogated by the expert system.Adopting the mainly graphical approach of data input, the expert system diagnoses reinforced concrete defects, proffers prognoses for concrete elements themselves (such as piers, columns, abutments), recommends testing regimes to confirm the expert system output, and recommends repair techniques.Should the recommendation of the expert system be to break out and replace defective concrete, the technique to recommend optimum repair material properties, developed in this research, will offer its recommendations.The developed expert system for reinforced concrete repair acts as an expert guide through all aspects of bridge inspection and repair. For the assessment of defects it draws together best practice recommendations from literature and experts. For the recommendation of repair material properties it implements the technique developed in the research.The completed research has been incorporated into a commercially available bridge management system (www.bridgemanagementexpert.com).