Why is concrete used for construction not only cement?

Why concrete is used for construction not only cement?

Concrete is widely used in the field of construction. Concrete consists of cement sand and aggregate where the quantity of cement defines the strength of concrete. Because the quantity of cement defines the strength of concrete, the question may arise in the mind that can we use only cement for construction, so the answer is simple and its No. Why? let's know more about it.

In the field of construction, we need a compound that is strong as well as economical. We use concrete in construction because it is not only strong but also economical, if compared with other construction materials. Then what about cement? Well, if we use only cement for construction it would not be economical, also the strength will be comparatively less than concrete.

Let's know why the strength of only cement is less than concrete.

If we are talking about strength. So the strength of concrete depends upon the following factors-

1. Water cement ratio
2. Quantity of cement
3. Grading of aggregates
4. Nature of aggregate

Concrete consists of cement, sand, and aggregates with optional admixtures. Because the aggregates present in concrete are well graded. Thus, the density of concrete is high i.e. the number of voids are less. A well-graded aggregate result in a great reduction of shrinkage which means the probability for the formation of cracks in concrete is less. While in the case of only cement block all the particles are of similar size which will directly reduce the density i.e. no of voids are more. More no of voids will introduce shrinkage in the cement block which means cracks will occur in the block of cement, thus decrease in the strength of the block.
There is a simple example for understanding this comparison-
The strongest concrete is M80 having a strength of 80Mpa and the highest grade of cement is 53 having a strength of 53 Mpa.