Structural evaluation of deteriorated reinforced concrete bridge columns and girders

Many existing reinforced concrete bridge structures deteriorate or exhibit extensive damage due to design and construction faults, chemical attacks or change in environment. Depending on the severity and type of deterioration, the bridge becomes unfit to serve its intended purpose, and repair may be required to restore and/or extend its service life. To develop a cost-effective repair plan, the remaining strength of bridge members must be investigated and estimated accurately. This paper presents structural evaluation of partially corroded reinforced concrete bridge columns and girders. It focuses on estimating the residual strength of concrete bridge members. This study is necessary to establish a cost-effective repair method for existing deteriorated bridges. Several variables were investigated, they include but not limited to: corrosion level, size of corroded region, percentage loss of rebar cross-section, level of degradation of bond between rebars and concrete. An advanced analytical approach is used to develop interaction diagrams of partially corroded reinforced concrete columns. These diagrams might be used to determine the strength and safety level of columns at the time of investigation. For the bridge girders, by using the preceding variables and the available test results, an analytical approach is presented to ascertain the proportion of loss of serviceability at the time of investigation.