Compressive Strength of Concrete Cylinders

The most common sample type for tests of concrete compressive strength is the concrete cylinder. There are other ways to determine concrete strength, and some methods may be more cost-effective and arguably better, but concrete cylinder testing remains the standard for acceptance.
Well-made concrete cylinders are easy and inexpensive to produce. Typically, one technician posted at the point of discharge or point of placement is sufficient to sample and test concrete batches for the slump, air content, unit weight, and cylinders. Technicians must follow standard practices and be certified in most regions, but training is neither extensive nor complex.

To determine the compressive strength of concrete cylinders.

Apparatus

 1) Compressive strength machine

Procedure

 1) Take out the cylindrical specimen from the curing tank.

 2)Wipe out the excess water from the surface of the specimen.

3)Place the specimen vertically on the platform of compression testing machine.

 4)Apply load continuously and uniformly without shock at the rate of 315KN/min and continue the  loading until the specimen fails.

Calculations

 1)Characteristic compressive strength at 28 days=     N/mm2

 2)Area of cross section=          mm2

 3)Expected load =Stress * area * factor of safety   KN

 4)Range to be selected=         KN

 5)Failure load=        KN

6)Characteristic compressive strength of concrete= failure load/cross sectional area  N/mm2

Result

Compressive Strength of Concrete Cylinders

Compressive Strength of Concrete Cylinders=         KN