What are the top and the bottom parts of the culvert barrel referred to as?

The correct term for the top and bottom parts of the culvert barrel is "slabs." In the context of civil engineering and drainage structures, a slab refers to a flat, horizontal structural element. In culverts, these slabs support the weight of the overlying material and provide structural integrity.

When considering other terms: "ends" typically refer to the terminal points of the culvert where it opens, "plates" are often associated with flat pieces of material used for various purposes but not specifically for the top and bottom parts of the barrel, and "decking" usually pertains to the surface covering on bridges or platforms rather than elements of a culvert structure. Understanding the correct terminology is essential for effective communication in construction and engineering projects.