Maintenance of early reinforced-concrete road bridges in Aberdeenshire, Scotland

This paper describes the development of long-term asset management plans for five early reinforced-concrete bridges in Aberdeenshire, Scotland. The bridges were constructed between 1924 and 1938 and are significant in terms of strategic importance and/or size, with total lengths ranging from 62 to 192 m. Identified defects included leakage, cracking, delamination, spalling and reinforcement corrosion. Detailed inspections, material testing and structural assessments were undertaken for each bridge to assess the current condition and capacity. Future deterioration models were developed to estimate when weight restrictions and replacement would become necessary and to determine optimal intervention dates. Several strategies were reviewed, including minimal maintenance, programmed maintenance, strengthening and replacement. Whole-life costs were developed for each strategy to identify the most cost-effective long-term solution.