Ad
related to: psi concrete testing
Search results
Results from the WOW.Com Content Network
Reactive powder concrete, also known as ultra-high-performance concrete, can be even stronger, with strengths of up to 800 MPa (116,000 PSI). [4] These are made by eliminating large aggregate completely, carefully controlling the size of the fine aggregates to ensure the best possible packing, and incorporating steel fibers (sometimes produced ...
Cubic or cylindrical samples of concrete are tested under a compression testing machine to measure this value. Test requirements vary by country based on their differing design codes. Use of a Compressometer is common. As per Indian codes, compressive strength of concrete is defined as: Field cured concrete in cubic steel molds (Greece)
Testing the compressive strength of a concrete cube using Schmidt hammer Cross section. The hammer measures the rebound of a spring-loaded mass impacting against the surface of a sample. The test hammer hits the concrete at a defined energy. Its rebound is dependent on the hardness of the concrete and is measured by the test equipment.
Concrete strength values are usually specified as the lower-bound compressive strength of either a cylindrical or cubic specimen as determined by standard test procedures. The strengths of concrete is dictated by its function. Very low-strength—14 MPa (2,000 psi) or less—concrete may be used when the concrete must be lightweight. [105]
The test is carried out using a metal mould in the shape of a conical frustum known as a slump cone or Abrams cone, that is open at both ends and has attached handles.The tool typically has an internal diameter of 100 millimetres (3.9 in) at the top and of 200 millimetres (7.9 in) at the bottom with a height of 305 millimetres (12.0 in).The cone is placed on a hard non-absorbent surface.
Regular concrete can typically withstand a pressure from about 10 MPa (1450 psi) to 40 MPa (5800 psi), with lighter duty uses such as blinding concrete having a much lower MPa rating than structural concrete. Many types of pre-mixed concrete are available which include powdered cement mixed with an aggregate, needing only water.
Duff A. Abrams (1880–1965) was an American researcher in the field of composition and properties of concrete. He developed the basic methods for testing concrete characteristics that remain in use. A professor with the Lewis Institute, he studied the component materials of concrete in the early 20th century.
Pervious concrete has a common strength of 600–1,500 pounds per square inch (4.1–10.3 MPa) though strengths up to 4,000 psi (28 MPa) can be reached. There is no standardized test for compressive strength. [15] Acceptance is based on the unit weight of a sample of poured concrete using ASTM standard no. C1688. [16]
Ad
related to: psi concrete testing