What type of lead was primarily used in the construction of bridges?

Red lead was primarily used in the construction of bridges because of its properties that make it an excellent primer and corrosion-resistant coating for metal structures. Composed mainly of lead(II,IV) oxide, red lead serves to protect steel and other metals from rust and degradation, which is particularly important in outdoor structures like bridges that are exposed to harsh environmental conditions.

This type of lead paint offers a durable finish and adheres well to metal surfaces, helping to preserve structural integrity over time. While other types of lead may be used in various applications, their functions and chemical properties do not align as closely with the needs of bridge construction. Knowing this helps in understanding the historical context of lead usage in construction and the importance of proper coatings in maintenance and safety.