Hardened Cement Concrete Properties


1. Strength of concrete:

The physical strength of cement concrete is basically defined as characteristic compressive strength and it totally depends upon different factors.

1- Binder material paste strength  
2- Interfacial bonding between aggregate and binder 
3- Aggregate strength value

1.Binder material paste strength:

It is basically due to the binding properties of cement/binding material, that is the ingredients are compacted to together. It has been observed that the cement paste has higher binding strength, higher will be strength of cement concrete.

2. Interfacial bonding between aggregate and binder :

Interfacial bonding between aggregate and binder is very much necessary regarding the strength of cement concrete. Clay hampers is the basic bonding between binder paste and aggregate. The coarse or fine aggregate should be washed/cleaned for a better bonding between cement paste and aggregate.

3. Aggregate strength value:

It is mainly the aggregate that provide the strength to concrete especially coarse aggregates portions which functionally act just like skeleton in the body. Rough,irregular and angular type of aggregate basically provides better bonding grip and high strength value.

Factors which affecting the Strength of cement concrete:

Following are the important factors that affect the strength of cement concrete:

1. Water-Cement ratio of concrete 
2. Type of cementing material used in concrete 
3. Amount of cementing material used in concrete 
4. Type of aggregate used in concrete 
5. Air content exist in concrete
6. Admixtures used in concrete

1. Water-Cement ratio of concrete:

The water cement ratio that generally governs the property of strength cement concrete. Comparatively lesser amount of water cement ratio, gives greater will be strength of cement concrete.

2. Type of cementing material used in concrete:

Different type of cement that affect the hydration process of concrete and therefore strength of cement concrete.

3. Amount of cementing material used in concrete: It is the binder paste material that holds or binds all the ingredients inside concrete. So, greater amount of cementing material gives greater will be strength of concrete.

4. Type of Aggregate used in concrete:

Rough,irregular and angular coarse aggregates is most preferable as they provide greater bonding strength.

5.Air content exist in concrete:Air entraining agent/ small bubbles of air increase the workability of concrete.It is also affect on the strength of concrete.

6. Admixtures used in concrete:

Chemical admixtures like plasticizers or superplasticizers reduce the water consumption and water cement ratio and increase the strength of concrete at same value of water cement ratio. Mineral admixtures also may some time used in concrete, which affect the strength of concrete at later stage and increase the strength of concrete by increasing the amount of cementing or binding material.