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The flow table test or slump-flow test is a method to determine consistency of fresh concrete. Flow table test is also used to identify transportable moisture limit of solid bulk cargoes. [ 1 ] It is used primarily for assessing concrete that is too fluid (workable) to be measured using the slump test , because the concrete will not retain its ...
Self-consolidating concrete or self-compacting concrete (SCC) [1] is a concrete mix which has a low yield stress, high deformability, good segregation resistance (prevents separation of particles in the mix), and moderate viscosity (necessary to ensure uniform suspension of solid particles during transportation, placement (without external compaction), and thereafter until the concrete sets).
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.
Concrete creep is essentially the sagging of concrete over time. Creep and shrinkage of concrete are two physical properties of concrete.The creep of concrete, which originates from the calcium silicate hydrates (C-S-H) in the hardened Portland cement paste (which is the binder of mineral aggregates), is fundamentally different from the creep of metals and polymers.
Abrams investigated the influence of the composition of concrete mixes on the strength of the end product. Some of the results of his research were: the definition of the concept of fineness modulus; the definition of the water–cement ratio; a concrete slump test for the
In the category of self-leveling concrete there are two main groups of materials: underlayments and toppings. An underlayment is installed over an existing subfloor to smooth it out and correct any surface irregularities prior to the installation of all types of floor coverings, including sheet vinyl, vinyl composition tile (VCT), wood, ceramic tile and carpet.
The effect of the water-to-cement (w/c) ratio onto the mechanical strength of concrete was first studied by René Féret (1892) in France, and then by Duff A. Abrams (1918) (inventor of the concrete slump test) in the USA, and by Jean Bolomey (1929) in Switzerland.
Concrete has a very low coefficient of thermal expansion, and as it matures concrete shrinks. All concrete structures will crack to some extent, due to shrinkage and tension. Concrete which is subjected to long-duration forces is prone to creep. The density of concrete varies, but is around 2,400 kilograms per cubic metre (150 lb/cu ft). [1]