No-one knows how the bridge concept really began but early man would have used fallen trees, stepping stones and other naturally occurring materials to cross geographical barriers. It was in the 18th Century that bridge design began to develop into a science, led by an engineering school founded in Paris. Its director, Jean Perronet, perfected the masonry arch, with its low-sweeping curve and slender piers. Just when the masonry arch bridge was reaching its peak around the beginning of the 20th Century, reinforced concrete arrived on the scene. Its use as a primary construction material has been an integral part of many bridges ever since.
展开▼
