The bridge consists mainly of iron and concrete. In the case of bridges where those are constructed along coastal areas, it is necessary to take into account chemical erosion of the materials due to chloride damage.
By observing the presence of cracks on the bridge structure, chemical analysis of the material, stresses which apply on the structure, etc. the bridge can be quantitatively assessed.
Recently BIM is utilized for construction works, these data are expected to be reflected in BIM. Then the maintenance planning and works would be performed effectively.