Workability of Concrete 

Workability: Workability of concrete can be defined as,  the easy with which the concrete ingredients can be  mixed, transported, placed, compacted and finished with minimum homogeneity  loss.

Factors Affecting Workability of Concrete:

1) Water content at concrete mix

2) Quantity of cement and its property

3) Gradation of Aggregate

4) Humidity of Environment 

5) Mode of Compaction.

6) Method of Mixing

7) Method of transmission

8) Method of Placement 

9) Weather Condition  etc.  

Importance of Workability of Concrete:

Any concrete mixture needs to be sufficiently workable to be properly placed and consolidated with the available procedures to fill the forms completely and surround the reinforcement and other embedded  item.

Methods of Improving Workability of Concrete:

Following measures can be taken to increase workability:

i)  Increasing water/cement ratio

ii) Using well-rounded and smooth aggregate instead of irregular shape.

iii) Using larger aggregate

iv) Using non-porous and saturated aggregate

v)  Increasing the mixing time and mixing temperature

vi) With addition of air-entraining mixtures

vii) Adding appropriate admixtures

 

Workability of Concrete can be Measured by:

1) Slump test method.

2) Vee-Bee test method.

3) Compaction factor test.

Importance of Soundness Test of Cement

Soundness: The ability of cement to retain its   volume after it gets hardened is known as the Soundness of Cement. 

Once the cement mortar or concrete gets dried there should not be any alteration in volume. If any alteration in volume occur, it will allow the cement to inflate or contract which leads crack in dried cement paste or concrete.This type of cement called unsound cement.

As we know lime is the main composition ( about 60-70%) of cement.  The test conducted to calculate the excess quantity of lime in cement is called soundness test of cement.