The military uses blast protection barriers known as T-Walls. These walls come in various sizes, and go by differing names depending upon their size. A Jersey Barrier type T-Wall, for instance, usually stands about 2 feet 8 inches tall, while an Alaska Barrier may stand 10 or even 12 feet tall. Technically speaking, an Alaska Barrier, Jersey Barrier and T-Wall constitute different things, though T-Wall is often used as a catchall for all such blast protection barriers. Jersey barriers were initially developed by the New Jersey state highway department, hence the name.
A construction T-Wall posses a standard, flat wall surface and a long concrete structure the extends perpendicularly from the back of this wall. Builders use these structures as retaining walls. Applications for such T-Walls include bridges, railway stations and residential barrier walls.
Both types of T-Walls consist of reinforced concrete. These reinforced concrete structures constitute enormous solid blocks of poured concrete with steel beams called rebar placed inside them for structural support. Companies manufacture T-Walls by pouring wet, claylike concrete into a mold, placing steel reinforcements in the mold within the wet concrete, and allowing the concrete to dry into a solid piece of material with the reinforcing bars inside it to ensure its structural integrity.
T-Wall manufacturers measure the amount of concrete in a T-Wall by weight. According to Defencell USA, a blast barrier manufacturer, the average 20 foot long Jersey wall weights about 8,000 pounds. Almost all of this weight comes from the concrete. An article published in British magazine Ingenia reports that T-Walls used to protect British forces in Afghanistan and Iraq weigh 6 tons, or 12,000 pounds. Companies that manufacture construction T-Walls often make units individually, specific to the need of a job. Determining the total concrete weight in any T-Wall requires subtracting the weight of steel used from the total weight of the wall.
You can calculate concrete in terms of volume in addition to calculating it by weight. In order to determine the full volume of concrete in a T-Wall, you need the dimensions of the mold used to create the wall. Using the dimensions of the mold, you can calculate volume using geometric formulas for determining volume in three-dimensional shape and subtracting the total volume of the steel used to reinforce the concrete. Contact the manufacturer of a T-Wall to determine the volume of the mold used, or measure a T-Wall to get the dimensions of the inside of the mold. Manufacturers may also simply provide you with volume measurements if you contact them.