"Mix design of concrete and properties of green concrete "5th semester civil engineering notes

     MIX DESIGN OF CONCRETE AND PROPERTY OF GREEN CONCRETE

Introduction:

Mix Design :Mix design can be defined as the process of selecting suitable ingredients of concrete and determining their proportion with the view to produce concrete of certain minimum strength and durability as economically as possible. 

Workability:

Work ability of concrete is defined as the ease with which the concrete can be mixed, transported, placed and compacted.It is usually defined in terms of the amount of mechanical energy or work, required for  compacting concrete without segregation. 

Factors affecting workability:

(1)Water content:Higher the  water content ,higher is work ability of the concrete mix and viceversa.

(2)Size of aggregate :The bigger size of aggregate will provide higher work ability to concrete mixes. 

(3)Grading  of aggregate :Better gradation of aggregate used provides high work ability. 

(4)Mixing temperature :As the mixing temperature increases, the work ability decreases and vice-versa. 

(5)Admixture:Admixture like superplasticizer can improve work ability.