Search results
Results from the WOW.Com Content Network
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. By reference to a conversion chart, the rebound value can be used to determine the concrete's compressive strength. When conducting the test, the hammer should be held at right angles to the ...
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.
CPT and CPTU testing equipment generally advances the cone using hydraulic rams mounted on either a heavily ballasted vehicle or using screwed-in anchors as a counter-force. One advantage of CPT over the Standard Penetration Test (SPT) is a more continuous profile of soil parameters, with data recorded at intervals typically of 20 cm but as ...
γ′ is the effective unit weight when saturated or the total unit weight when not fully saturated. B is the width or the diameter of the foundation. φ′ is the effective internal angle of friction. K pγ is obtained graphically. Simplifications have been made to eliminate the need for K pγ. One such was done by Coduto, given below, and it ...
Saturated unit weight The unit weight of a soil when all void spaces of the soil are completely filled with water, with no air. The formula for saturated unit weight is: = (+) + where γ s is the saturated unit weight of the material; γ w is the unit weight of water; G s is the specific gravity of the solid; e is the void ratio [3] Submerged ...
The ultimate strength of concrete is influenced by the water-cementitious ratio (w/cm), the design constituents, and the mixing, placement and curing methods employed.All things being equal, concrete with a lower water-cement (cementitious) ratio makes a stronger concrete than that with a higher ratio. [2]
Changes of pore water content due to drying or wetting processes cause significant volume changes of concrete in load-free specimens. They are called the shrinkage (typically causing strains between 0.0002 and 0.0005, and in low strength concretes even 0.0012) or swelling (< 0.00005 in normal concretes, < 0.00020 in high strength concretes).
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.