Workability of Concrete !!!!!

Definition

Workability is the property of fresh concrete which is indicated by the amount of useful internal work required to fully compact the concrete without bleeding or segregation in the finished product. Workability is one of the physical parameters of concrete which affects the strength and durability as well as the cost of labor and appearance of the finished product. Concrete is said to be workable when it is easily placed and compacted homogeneously i.e. without bleeding or segregation. Unworkable concrete needs more work or effort to be compacted in place, also honeycombs or pockets may also be visible in finished concrete. 

Factors affecting workability of concrete  

• Water cement ratio
• Amount and properties of cement
• Aggregate Grading
• Nature of aggregate particles ( Shape,Surface Texture, Porosity etc.)
• Temperature of concrete mix
• Humidity of the environment
• Method of transmission of concrete
• Method of placement of concrete
• Mode of compaction

 Methods to improve the workability

• Increase water cement ratio
• Increase size of aggregate
• use well-rounded and smooth aggregate instead of irregular shape
• Increase the mixing time
• Increase the Mixing Temperature
• Use non porous and saturated aggregates
• Adding air-entraining mixtures

 Methods to test the workability of concrete

• Slump Test
• Flow test
• Vee-Bee Consistometer Test
• Kelly Ball Test (Ball Penetration Test)