Tests on Cement and Concrete Mixes
Compressive Strength
Code: This test is done as per (IS:4031-Part 6-1988).
Test Procedure:
- i) Take 200 g of cement and 600 g of standard sand and mix them dry thoroughly.
- ii) Add of water (where P is % of water required for preparing paste of standard consistency) to the dry mix of cement and sand and mix thoroughly for a minimum of 3 minutes and maximum of 4 minutes to obtain a mix of uniform colour. If even in 4 minutes uniform colour of the mix is not obtained reject the mix and mix fresh quantities of cement, sand and water to obtain a mix of uniform colour.
- iii) Place the thoroughly cleaned and oiled (on interior face) mould on the vibrating machine and hold it in position by clamps provided on the machine for the purpose.
- iv) Fill the mould with entire quantity of mortar using a suitable hopper attached to the top of the mould for facility of filling and vibrate it for 2 minutes at a specified speed of 12000±400 per minute to achieve full compaction.
- v) Remove the mould from the machine and keep it in a place with temp of 27±20C and relative humidity of 90% for 24 hours.
- vi) At the end of 24 hrs remove the cube from the mould and immediately submerge in fresh clean water. The cube be taken out of the water only at the time of testing.
- vii) Prepare at least 6 cubes in the manner explained above.
- viii) Place the test cube on the platform of a compressive testing machine without any packing between the cube and the plates of the testing machine.
- ix) Apply the load steadily and uniformly, starting from zero at a rate of 35 N/mm2/minute.
Uses:
To find out the strength of cement.