This synthesis reports on the methods currently used to increase live load capacity of existing highway bridges. It covers methods used in the past 10 years by North American transportation agencies that responded to a survey, and internationally through a literature search, for bridges predominately in the short-to medium-span range. The more common bridge types and construction materials (e.g., steel, reinforced concrete, prestressed concrete, and wood) are addressed with emphasis on superstructure strengthening rather than substructure. This synthesis will be of interest to state department of transportation bridge design and structural engineers, bridge consultants, and others involved in applied and research methods for increasing the live load capacity of existing highway bridges. The synthesis describes the current state of the practice for the various methods used to increase the live load capacity of existing highway bridges. This is done predominantly for bridges in the short- to medium-span range. Information on the more common bridge material types is presented. There is an emphasis on superstructure rather than substructure strengthening. (A)
Samenvatting