Pier (bridge structure)

Roman bridges were sturdy, semicircular, and rested on thick piers, with a width equal to about half the span of the vault.

[5] Considerable progress was then made with the invention of modern natural cement discovered in 1791 by James Parker in England and especially through the work of Louis Vicat in France (1813–1818) who laid the foundations of the hydraulic binders industry and thus of concrete.

The alliance with steel gave birth to reinforced concrete, allowing the construction of increasingly daring and economical structures.

Paul Séjourné would be the last great theorist of masonry bridges, and his methods and formulas for calculating piers remain relevant today.

As early as 1937, considerable height was reached with the Golden Gate Bridge in the United States, which has pylons 230 meters tall.

In masonry bridge piers, there is a resistant part and a filling part:[6] The dimensions of the supports result from the consideration of four criteria: stability against overturning, compression resistance of the support masonry, permissible pressure on the ground, and aesthetics.

A ratio E/C below 0.4 generally corresponds, with common cements, to the domain of HPC (the strength then exceeds 50 MPa).

In practice, to overcome the decrease in workability of the concrete due to low E/C ratios, superplasticizers are used to deflocculate the fines (cement, mineral additions, ultra-fines).