In a retaining wall, these blocks are stacked together in ... Before pouring, steel rebar is usually placed into the forms according to an engineer's specifications. Then, the crews pour the ...

U.S. Army Corps of Engineers (USACE) contractors place rebar at footing of retaining walls on June 20, 2019, in Calexico, Calif. (Photo by Mani Albrecht/U.S. Customs and Border Protection) Department ...