Factors Influencing the Strength of Concrete:

The strength of concrete is a function of strength of cement paste matrix, which generally increases with quantity of cement and decreases with quantity of water. The strength of concrete is proportional to the degree of hydration and inversely proportional to the porosity of the concrete. The other factors on which the strength of concrete depends are water cement ratio, degree of compaction, age of concrete, temperature and properties of aggregates. Out of these, the water cement ratio being the most important factor.

Commonly, the strength of concrete increases along with degree of compaction because porosity reduces with the amount of compaction. The effect of properties of aggregate and degree of compaction on the strength of concrete. The effect of other two factors (i.e. age of concrete and temperature) on strength of concrete is explained in the subsequent paragraphs.