Paper Title
Health Monitoring Method for Concrete Slab in Bridge With Functional Declined Bearing

Abstract
The functions of movable bearings decline due to corrosion and sediments. As the result, they cannot move or rotate in response to the behaviors of girders. Because of the constraints, the bending moments are generated by the horizontal reaction forces and the heights of girders. Under these conditions, the authors obtained the results by analyses. Tensile stresses due to the moments occurred at temperature fluctuations. The large tensile stress on a concrete slab around the bearings caused cracks. When the widths of cracks increase and steel bars in a concrete slab corrode, the concrete slab may have to be replaced. Even if concrete slabs are newly replaced, cracks will come out again with function declined bearings. By using SOFO sensor that can be fixed with magnets on a steel bridge, it is possible to easily measure the strain of the upper and lower of the web. It is also possible to estimate the stress occurred on the concrete slab from the strain distribution on the girder. Engineers can judge if cracks occur using their results. Index terms: Bridge bearing, Concrete slab, SOFO sensor, Health monitoring