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Factors affecting workability

Short answer

Workability is the ease with which concrete can be mixed, transported, placed, compacted, and finished without segregation. Factors: water content, w/c ratio, aggregate properties (shape, size, grading), cement fineness, admixtures, temperature, time after mixing.

Define workability. List the factors that affect the workability of concrete.

Workability is the property of freshly mixed concrete that decides how easily it can be mixed, transported, placed, compacted and finished without segregation (IS 6461).

Factors affecting workability

  1. Water content: more water gives higher workability (the main factor).
  2. Water-cement ratio and cement content / paste volume.
  3. Aggregate properties: shape (rounded is better), texture (smooth is better), maximum size (larger gives higher workability), grading (well graded is better), and porosity/absorption.
  4. Aggregate-cement ratio and fine-to-coarse aggregate ratio.
  5. Fineness and type of cement.
  6. Admixtures: plasticisers, superplasticisers and air-entraining agents raise it; accelerators lower it.
  7. Temperature: high temperature reduces workability (faster hydration and evaporation).
  8. Time: slump is lost as time passes after mixing.
  9. Method of mixing and compaction (mixer type, mixing time), and environmental conditions such as humidity and wind.

✓ Answer checked by Claude Opus 5.5 (high effort)

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