As Civil Engineers, We all know that microstructure of concrete is very important in terms of strength durability and serviceability. Many deleterious actions operate through microstructure of concrete therefore, it is very important that we should try to improve it. We can improve microstructure of concrete by following these steps.
1) Mixing Water/Cement Ratio
w/c ratio in any concrete formulation plays a huge role in determining the microstructure and strength of the system. Higher mixing water gives low strength because of higher porosity and maximum pore size.
To ensure that adequate mixing water is used it is recommended that mixing water content should be within 35 to 40 or ideally speaking the mixing water content should be equal to demand of the system.
2) Using Suitable Admixtures
Admixtures both mineral, as well as chemical, can be used to improve microstructure. Super Plasticizers (chemical admixture) can be used to increase flow at relatively low w/c ratio. Amorphous mineral admixtures can be used to give a pozzolanic reaction.
3) Using Regular Aggregate shape
It is desirable that aggregate shape should be uniform. Flaky and elongated aggregates should be avoided as they tend to weaken the overall structure.
4) Grading Of Aggregate
Grading of aggregates should be optimized so that there is an optimum range of aggregate sizes available. This will ensure that physical packing is there in the hardened state of concrete.
5) Poor Workman Ship
Take steps to avoid poor workmanship at erection time so that site work is carried out according to design specifications.