The strength & longevity as well as the cost of labor and look of the finished product is greatly impacted by the workability of concrete. The concrete can provide better functionality, if it is easily positioned and compacted consistently devoid of bleeding or Segregation.
The concrete that is not in good working condition should be supported with extra work and endeavor for being compacted in position, also honeycombs &/or pockets are also found in finished concrete.
Definition of Workability: Concrete workability defines how smoothly freshly mixed concrete is amalgamated, arranged, compacted and finished by keeping the conformity as it is. Workability refers to a property that directly affects strength, quality, appearance, as well as the cost of labor for placement and finishing operations.
The workability is impacted with the following factors :
1. Water content in the concrete mix
2. Amount of cement & its Properties
3. Aggregate Grading (Size Distribution)
4. Nature of Aggregate Particles (Shape, Surface Texture, Porosity etc.)
5. Temperature of the concrete mix
6. Humidity of the environment
7. Mode of compaction
8. Method of placement of concrete
9. Method of transmission of concrete
The workability of concrete can be improved in following ways :-
1. Raise the proportion of water/cement
2. Raise size of aggregate
3. Apply well-rounded and smooth aggregate rather than asymmetrical shape
4. Rise the mixing time
5. Enhance the mixing temperature
6. Employ non-porous and saturated aggregate
7. Include air-entraining mixtures
The most recognized method for measuring the workability of concrete is Slump Test.