CONCRETE TEST

CONCRETE TEST.

before casting a concrete... the material will be tested to ensure workability.

slump test:
slump test would be normally tested on site during the arrival of material to the site.
with the request of a quantity surveyor.. material must be tested to ensure quality and workability achieved before approving payment for the order.

how to conduct a slump test?
- get a sample of the material ordered
- includes cement, fine & coarse aggregate and water. (normally)
- fill in the mixture into the slump cone as shown. 

 

- pull of the slump cone and see whether the mixture is collapse or not.

 

-measure the height as shown above if it doesn't fully collapse. if its collapse the whole material will be reject as it could not reach the workability level requested.

- (if didn collapse) at the end cast a concrete and when its hardened put the concrete into water for further test.

 

COMPACTING FACTOR TEST

 

1.     In the testing process, the concrete firstly is loaded into the upper hopper

2.     After that, the trap door is open to allow the concrete falls into the lower hopper

3.     Then, the next trap door is open to allow the concrete fall into the cylinder

4.     The concrete is stuck off level with the top of the cylinder

5.     Next, the concrete in the cylinder is weighed together, to give the partially compacted weight of concrete

6.     The concrete is compacted fully and extra concrete will be added to fill the cylinder

7.     Finally, the cylinder and concrete is weighed to give the fully compacted weight of concrete

the formula of compacting factor =       Weight of partially compact concrete

                                                            Weight of fully compact concrete   

 

VEBE TEST

           

1.     Firstly, a slump test is performed in a container

2.     Next, a clear Perspex disc which can free to move vertically, is lowered onto the concrete surface

3.     Vibration with the standard rate is applied

 

FLOW TABLE TEST

                                     

       

1.     At the first, a conical mould which smaller than that of the standard slump test, is used to produce a concrete sample in the centre of a 700mm square board, hinged along one edge.

2.     The free edge of the board is lifted against the stop and dropped 15 times.

3.     The formula of flow = final diameter of the concrete.