IMPORTANT POINTS TO REMEMBER AT THE TIME OF CASTING, CURING AND TESTING OF CONCRETE CUBES

AT THE TIME OF CASTING OF CONCRETE CUBES 

1. Check dimensions & right angles of cube mould and apply mould oil.

2. Filling of cube moulds must be done in three layers each 50 mm thick.

3. Fill the concrete using the scoop & scoop should be moved around the top edges of the cube mould so that symmetrical distribution of the concrete is done in each layer.

4. Each layer must be compacted fully using tamping rod with 35 strokes in each layer (in case of hand compaction)

5. Each layer must be compacted fully using table vibrator. Care is be taken to see all entrapped air should be come out.

6. Tamp the sides of the mould by wooden mallet to avoid entrapment of air.

7. Put identification mark, date & grade of concrete on wet concrete.

‘CURING’ OF CUBE

1. Strip the mould after 16-24 hrs. Without damaging the edges of & surface of cube

2. Submerge the specimen in the curing pound containing clear water till such time it is due for testing.

3. Water in curing tank must be fresh (changed after 7 days)

4. Level of water in curing tank must be such that cube is completely immersed in water.

1. Remove any loose particles from specimen

2. Check weight of cube before testing.

3. Cube should be placed in compression testing machine such that smooth faces of the cube rest on steel plates. the face of the cube which is trowel finished should never be brought in contact with m/c as it will cause unsymmetrical loading due to uneven surface compared to other faces witch are smooth.

4. Apply the load uniformly until the concrete cube breaks or is crushed.

5. Take down the reading & calculate the strength.