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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 addition of an accelerator speeds the setting time and thus cure time starts earlier. [1] This allows concrete to be placed in winter with reduced risk of frost damage. [2] Concrete is damaged if it does not reach a strength of 500 pounds per square inch (3.4 MPa) before freezing. [3]: 19
Accelerated curing is any method by which high early age strength is achieved in concrete. These techniques are especially useful in the prefabrication industry, wherein high early age strength enables the removal of the formwork within 24 hours, thereby reducing the cycle time, resulting in cost-saving benefits. [ 1 ]
Visible frost damage develops after an accumulation of micro-cracks as a result of several freeze-thaw cycles. [ 1 ] [ 2 ] Frost damage can be prevented by the use of frost-proof materials, i.e. , a material which has sufficient closed pores, by which the volume increase caused by the freezing of water in capillary pores can be absorbed by the ...
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]
Axon and elevation diagram of lift slab construction. Lift slab construction (also called the Youtz-Slick Method) is a method of constructing concrete buildings by casting the floor or roof slab on top of the previous slab and then raising (jacking) the slab up with hydraulic jacks. This method of construction allows for a large portion of the ...
The tremie concrete placement method uses a vertical or nearly vertical pipe, through which concrete is placed by gravity feed below water level. [4]The lower end of the pipe is kept immersed in fresh concrete so that concrete rising from the bottom displaces the water above it, thus limiting washing out of the cement content of the fresh concrete at the exposed upper surface.
Concrete has a relatively high thermal mass, meaning that it takes a long time to respond to changes in ambient temperature. [9] This is a disadvantage when rooms are heated intermittently and require a quick response, as it takes longer to warm the entire building, including the slab.