The Concrete Calculator estimates the volume and weight of concrete necessary to cover a given area. Purchasing slightly more concrete than the estimated result can reduce the probability of having insufficient concrete.
Slabs, Square Footings, or Walls
|Volume:||27 cubic feet|
or 1 cubic yards
or 0.76 cubic meters
|Weight needed||3,591 lbs or 1,628.5 kg|
|Using 60-lb bags||59.85 bags|
|Using 80-lb bags||44.89 bags|
Hole, Column, or Round Footings
Circular Slab or Tube
Curb and Gutter Barrier
Concrete is a material comprised of a number of coarse aggregates (particulate materials such as sand, gravel, crushed stone, and slag) bonded with cement. Cement is a substance that is used to bind materials, such as aggregate, by adhering to said materials, then hardening over time. While there are many types of cement, Portland cement is the most commonly used cement, and is an ingredient in concrete, mortar, and plasters.
Concrete can be purchased in multiple forms, including in 60 or 80-pound bags, or delivered in large amounts by specialized concrete mixer trucks. Proper mixing is essential for the production of strong, uniform concrete. It involves mixing water, aggregate, cement, and any desired additives. Production of concrete is time-sensitive, and the concrete must be placed before it hardens since it is usually prepared as a viscous fluid. Some concretes are even designed to harden more quickly for applications that require rapid set time. Alternatively, in some factory settings, concrete is mixed into dryer forms to manufacture precast concrete products such as concrete walls.
The process of concrete hardening once it has been placed is called curing, and is a slow process. It typically takes concrete around four weeks to reach over 90% of its final strength, and the strengthening can continue for up to three years. Ensuring that the concrete is damp can increase the strength of the concrete during the early stages of curing. This is achieved through techniques such as spraying concrete slabs with compounds that create a film over the concrete that retains water, as well as ponding, where concrete is submerged in water and wrapped in plastic.