ðŸ•‘ Reading time: 1 minute

Strength of concrete is generally tested after 28 days as concrete cube strength or concrete cylinder strength. The reason for testing concrete strength after 28 days is discussed.**Why do we test concrete compressive strength after 28 days?**

Concrete gains strength with time after casting. It takes much time for concrete to gain 100% strength and the time for same is still unknown. The rate of gain of concrete compressive strength in higher during the first 28 days of casting and then it slows down.
The table below shows the compressive strength gained by concrete after 1, 3, 7, 14 and 28 days with respect to the grade of concrete we use.
Age |
Strength per cent |

1 day | 16% |

3 days | 40% |

7 days | 65% |

14 days | 90% |

28 days | 99% |

**Read More:**

**Concrete - Definition, Grades, Components, Manufacture, Construction and Articles**

**Compressive Strength of Concrete Cubes**

**Planning In-Situ Testing of Concrete for Strength, Durability and Damages**