Which deck material is the most common due to its variable shapes and construction methods?

Concrete is indeed the most common deck material used in bridge construction primarily because of its versatility in shape and the variety of methods available for its construction. Concrete decks can be cast in place or precast, allowing for flexibility based on the specific needs of a bridge design, site conditions, and construction timelines.

Moreover, concrete is capable of being molded into complex geometries, which can accommodate various span lengths and load requirements. This adaptability makes it ideal for a wide range of bridge types, from small pedestrian bridges to large highway overpasses. Concrete also has good durability and strength characteristics, which contribute to its popularity in infrastructure projects.

In contrast, while materials like timber, steel, and composite materials are used in bridge decks, they often come with limitations. Timber typically has a more restricted lifespan, steel may require significant maintenance against corrosion, and composite materials, while advantageous in certain contexts, often convey higher costs and complexity in construction compared to traditional concrete. Hence, the predominance of concrete in bridge decks is attributed to its unmatched adaptability, strength, and the variety of construction techniques it supports.