Bridgeworks: construction and maintenance
All roads have associated bridgeworks where they cross rivers, railways and other roads. Hence, bridges form a major feature of the road system of the country. The advent of Drones has reduced the risk when undertaking bridge inspections using modern camera and video technology. A footbridge is to consist of natural stone abutments and timber decking and is to be constructed over a stream approximately 2 m wide. Any timber used in bridges should be either naturally resistant to decay or sufficiently permeable to allow adequate preservation treatment. Concrete bridge structures may be subjected to a number of damaging substances, mainly in the form of chemical solutions, which attack the concrete, causing both deterioration of the strength of the concrete and corrosion of the embedded reinforcement. Concrete bridge structures may frequently suffer from reinforcement corrosion induced by penetration of de-icing salt.