Bridge Rehabilitation

In the last two decades, the rapid deterioration of bridge structures has become a serious technical and economical problem in many countries, including highly developed ones. Therefore, bridge rehabilitation has also become a very essential factor (sometimes even a decisive one) in contemporary bridge engineering. The book covers in synthetic form nearly all the most important problems concerning bridge rehabilitation, such as bridge superstructure and substructure, the typical damage observed in bridges as well as the assessment and evaluation techniques of their technical condition. The book is intended mainly for postgraduate university students. Therefore, all the problems are mostly presented in their physical, chemical and technical as well as economical aspects. The relevant requirements are treated as objective ones, i.e. irrespective of the rules, standards, regulations or guidelines particular to any country. This approach to the subject gives the book a more general character and therefore makes it a useful text for most civil engineering courses./a

This report presents a literature search, findings of a survey on the current state of historic bridge rehabilitation or replacement decision making by state and local transportation agencies, and nationally applicable decision-making guidelines for historic bridges. The guidelines are intended to be used as the protocol for defining when rehabilitation of historic bridges can be considered prudent and feasible and when it is not based on engineering and environmental data and judgments. The guidelines include identification of various approaches to bringing historic bridges into conformance with current design and safety guidelines/standards, and the effect or implications of remedial action on historical significance. There are currently no such nationally applicable decision-making guidelines, but there are a variety of state and local processes and policies for managing historic bridges. Effective practices for the various processes inform the nationally applicable guidelines. The guidelines are in narrative and matrix format.

Evaluation, repair and rehabilitation of bridges are increasingly important topics in the effort to deal with the deteriorating infrastructure. For example, in the United States about 40 percent of the nation's 570,000 bridges are classified, according to the Federal Highway Administra tion's (FHW A) criteria, as deficient and in need of rehabilitation and replacement. In other countries the situation is similar. FHW A estimates the cost of a bridge replacement and reha bilitation program at 50 billion dollars. The major factors that have contributed to the present situation are: the age, inadequate maintenance, increasing load spectra and environmental contamination. The deficient bridges are posted, repaired or replaced. The disposition of bridges involves clear economical and safety implications. To avoid high costs of replacement or repair, the evaluation must accurately reveal the present load carrying capacity of the struc ture and predict loads and any further changes in the capacity (deterioration) in the applicable time span. Accuracy of bridge evaluation can be improved by using the recent developments in bridge diagnostics, structural tests, material tests, structural analysis and probabilistic methods. There is a need for an international exchange of advanced experience to increase the research effi ciency. The Workshop is organized on the premise that the exchange of existing American and European experience in the area of bridge evaluation, repair and rehabilitation is beneficial for both parties involved.

The First International Conference on Concrete Repair, Rehabilitation and Retrofitting (ICCRRR 2005) was held in Cape Town, South Africa, in November 2005. The conference was a collaborative venture by researchers from the South African Research Programme in Concrete Materials (based at the Universities of Cape Town and The Witwatersrand) and The Construction Materials Section at Leipzig University in Germany. The conference focused on appropriate repairing, maintaining, rehabilitating, and, if necessary, retrofitting existing infrastructure with a view to extending its life and maximising its economic return.