The book contains proceedings presented at the 9th International Conference on Arch Bridges held in Porto, Portugal on October 2 to 4, 2019. It is addressed to scientists, designers, technicians, stakeholders and contractors, seeking for an up-to-date view of the recent advances in the area of arch bridges.

Keynote lectures.- Heritage arch bridges.- Analytic and numerical studies of arch structures.- Experimental studies of arch structures.- Design and construction of arch bridges.- Rehabilitation, maintenance and condition assessment of arch bridges.- New and future trends in arch bridges.