When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. Properties of concrete - Wikipedia

    en.wikipedia.org/wiki/Properties_of_concrete

    Engineers usually specify the required compressive strength of concrete, which is normally given as the 28-day compressive strength in megapascals (MPa) or pounds per square inch (psi). Twenty eight days is a long wait to determine if desired strengths are going to be obtained, so three-day and seven-day strengths can be useful to predict the ...

  3. Schmidt hammer - Wikipedia

    en.wikipedia.org/wiki/Schmidt_hammer

    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 ...

  4. Compressive strength - Wikipedia

    en.wikipedia.org/wiki/Compressive_strength

    As per Indian codes, compressive strength of concrete is defined as: Field cured concrete in cubic steel molds (Greece) The compressive strength of concrete is given in terms of the characteristic compressive strength of 150 mm size cubes tested after 28 days (fck). In field, compressive strength tests are also conducted at interim duration i.e ...

  5. Types of concrete - Wikipedia

    en.wikipedia.org/wiki/Types_of_concrete

    High-strength concrete has a compressive strength greater than 40 MPa (6000 psi). In the UK, BS EN 206-1 [2] defines High strength concrete as concrete with a compressive strength class higher than C50/60. High-strength concrete is made by lowering the water-cement (W/C) ratio to 0.35 or lower.

  6. Concrete - Wikipedia

    en.wikipedia.org/wiki/Concrete

    The strength of concrete changes (increases) for up to three years. It depends on cross-section dimension of elements and conditions of structure exploitation. [50] Addition of short-cut polymer fibers can improve (reduce) shrinkage-induced stresses during curing and increase early and ultimate compression strength. [77]

  7. Gypsum concrete - Wikipedia

    en.wikipedia.org/wiki/Gypsum_concrete

    Gypsum concrete is lightweight and fire-resistant. A 1.5-inch slab of gypsum concrete weighs 13 pounds per square foot versus 18 pounds per square foot for regular concrete. [10] Even though gypsum concrete weighs less, it still has the same compressive strength as regular concrete, based on its application as underlayment or top coat flooring ...

  8. Strength of materials - Wikipedia

    en.wikipedia.org/wiki/Strength_of_materials

    A simple case of compression is the uniaxial compression induced by the action of opposite, pushing forces. Compressive strength for materials is generally higher than their tensile strength. However, structures loaded in compression are subject to additional failure modes, such as buckling, that are dependent on the member's geometry.

  9. Specific strength - Wikipedia

    en.wikipedia.org/wiki/Specific_strength

    It is also known as the strength-to-weight ratio or strength/weight ratio or strength-to-mass ratio. In fiber or textile applications, tenacity is the usual measure of specific strength. The SI unit for specific strength is Pa ⋅ m 3 / kg , or N ⋅m/kg, which is dimensionally equivalent to m 2 /s 2 , though the latter form is rarely used.