Bridge Inspection

19TH AVENUE, CITY OF MARKHAM, ONTARIO

This project involved the inspection of a reinforced concrete bridge in the City of Markham using the iCAMM inspection tool. The bridge/culvert was built in 1982, and has a span of approximately 6.7 m and a width of 13.4 m. The general concrete condition of the underside of the bridge (i.e., soffit) was assessed previously by others using visual assessment, half-cell survey, and coring (total of 6 cores, with measurements of air and chloride content and concrete compressive strength). There were visible signs of discoloration, delamination, cracking, scaling, and spalling on the concrete surface, indicating the presence of reinforcement corrosion.

InspecTerra used the proprietary iCAMM inspection tool to assess the condition of the reinforcing steel on the bridge soffit. Unlike destructive methods (i.e., coring) and other NDT methods, such as the half-cell survey, which require physical access to the underlying rebar, the condition of the rebar (i.e, degree of section loss due to corrosion) was measured by iCAMM directly from the concrete surface. In most rebar applications (i.e., depending on the rebar size), iCAMM can reliably measure the rebar condition under a 0 - 10 cm concrete cover depth.

The iCAMM results were in excellent agreement with the other methods, however, rather than only providing qualitative information about the corrosion potential or probability of corrosion taking place in certain areas, iCAMM provided quantitative estimates of the actual degree of section loss across the entire bridge deck.