Wednesday, 4 April 2018

Definition Of Concrete and Their Classification

What is Concrete

 When a binding material (cement or lime),fine aggregate (sand or surkhi) ,coarse aggregate such as crushed stone , broken bricks etc. and water are mixed in suitable proportion , they form an easily workable mix, known as plastic or green concrete. When this plastic concrete becomes hard like a stone , this is termed as hardened concrete or simply as concrete.

Classification of Concrete

concrete are classified as given below :

1)According to specification :-

a)Nominal mix concrete: 

The concrete which is prepared according to prescriptive specification i.e. proportion of constituents and their characteristics is termed as nominal mix concrete.

b)Designed mix concrete 

The concrete which is prepared according to performance oriented specifications i.e. strength ,workability etc. is termed as designed mix concrete.

 2)According to level of control:

a)Controlled concrete 

Controlled concrete is that concrete , in which preliminary test are conducted for designing the mix .In addition to mix proportioning ,level of control is also exercised in selection of materials batching , mixing ,transportation, compaction and curing along with necessary checks and tests for quality acceptance.

b)Ordinary concrete

Ordinary concrete is one where no preliminary tests are performed for designing the mix.

3)According to binding materials:-

a)Cement concrete

The concrete consisting of cement , sand and a coarse aggregate mixed in suitable proportion in addition to water is called cement concrete.

b)Lime concrete

The concrete consisting of lime, a fine aggregate and a coarse aggregate mixed in suitable proportion in addition to water is called lime concrete . The strength of this concrete is less but it is cheaper than cement concrete.

4)According to design:-

a)Plan cement concrete. 
b) Reinforced cement concrete.
c)Pre-stressed concrete.

5)According to purpose:-

a)Vacuum concrete b)Air –entrained concrete. c)Light weight concrete. 
d)sawdust concrete. 
e)High early strength concrete
f)White and colored concrete.