How can I increase the strength of concrete?
It is possible to increase the strength of concrete, keeping in mind the factors on which the strength of concrete depends.
The strength of concrete depends on the following factors.
1. mixing time - the strength of concrete increases with increasing mixing time up to 2 minutes, beyond which no significant increase in strength is observed. This becomes clearer with the graph below.
2. Type and age of cement - The variation of concrete strength with the type of cement is shown in the following graph -
As age increases, the strength of the cement decreases due to the absorption of more water from the atmosphere.
The quality of the cement also depends on the storage conditions of the cement, so the strength of the concrete also depends on the storage conditions of the cement as shown in the graph -
3. Type and size of aggregates - The degree of filling is the main factor to be considered here. The greater the degree of filling, the smaller the void ratio and the greater the strength.
Spherical or round aggregates provide more compaction than irregularly shaped aggregates. This is why they provide more strength.
It is a common belief that the larger the maximum size of an aggregate, the smaller its surface area, the lower its water-to-cement ratio, and the greater its strength. However, this is not true; a smaller surface area results in a smaller surface area for the gel bonds, which leads to lower strength.
4. Curing - The effect of curing can be understood by the following diagram -
Curing is essential to obtain optimum strength and durability. It is necessary to maintain the required moisture content as well as temperature conditions.
5. Water to ash ratio - As the water to ash ratio increases, the strength of the concrete decreases as shown in the following graph -