Concrete Vibrator Suggestions

[venkyn]

Hi,

To rent a vibrator it costs Rs 300/day. So, wondering if i use 33 times then i will be paying the cost of vibrator which 10K.
So, Which is best Concrete Vibrator, any brand or what needs to be looked in to vibrator before purchasing.

Any idea?

Regards,
Venky

[girish1984]

Hi Venky,

Is this a labor contract ? if yes, then while making agreement you should have left that to Mason.
Dont spend money on purchasing/renting for vibrator.
Mason will be having their own vibrator or they will rent by themselves for using for concrete work.It is their responsibility to have/put vibrator during concrete work.Please dont take this headache in renting/purchasing vibrator.Leave that to mason.

For my building, vibrator was used by Mason itself. Didn't spend a single penny on renting vibrator.

Regards,
Girish

[venkyn]

Hi Girish,

My contractor told me that rent has to borne by the owner. so, when i inquired i found out that it is cheaper to buy then renting it out.
The tendency is that they will compromise quality during concrete for columns,plinth beams etc to save Rs300/day.
So, some equipment should be present with owner then labor contractor.

[girishd]

Generally its contractor's responsibility to get vibrator for columns/roof. I was thinking you would need it at most 6-7 times in a 3-floor house - footings, roof and columns. The lentil beam or plinth beam which is less than 6-8 inches doesn't require vibrator.

[zipperboy]

Hi,

For my construction, (started sept beginning), vibrator was brought by contractor only, also petrol given by him.He is working under labour contract.
So maybe you can tell your contractor that he should be getting the vibrator as its the norm ( i think).

Regards
Asif

[vijaykumarthapa]

Hi Venky,
please go back to your contractor and advise its Contractors job to get vibrator and petrol. Its never owners burden.
looks like your contractor is taking you for a ride.

Vijay Thapa

[pribaaji]

yes its the contractors responsibility as the members have told , even i am building on labour contract and he got all the necessary equipments.

[ausraja]

Please note that using too much vibrator is not recommended as it drains the cement water portion of the concrete and leaves behind only sand and jelly.Ideally it must be used only in the joints where the column beam and slab meets not everywhere.

[civil88]

@Venkyn,

I know it is one thing to seek opinion from the forum members and quite another to convince your contractor to get the vibrator on his own. If he does not relent, go ahead and buy the vibrator. You can always sell it for half price or even more, once your building is completed.

Let me elaborate why buying is a better idea:
1. Concrete work as we all know is the most important part of a building. If the vibrator is not used sufficiently or properly, there are good chances of honeycomb formation. This means the 20mm aggregate stone gets segregated and appears like a honey comb once the shuttering for the columns or beams is removed.
2. If you rent a vibrator, unless the mason is very strict, the operator typically puts the vibrator for name-sake for a very short period and takes it out as if in a hurry. Why do they do this? As ausraja, mentioned the masons think that keeping the vibrator for longer duration will drain out the water. This is a totally wrong argument.
The work of a vibrator is pull out all the minute air voids that are present in a concrete mix. The masons typically pour more water than required to be able to pour the concrete easily into the column/beam. This is a wrong practice. You need to use a plasticizer (a chemical additive mixed along with water) to make sure the concrete is 'workable' while maintaining the water-cement ratio. Please remember that increasing water content is not good for your concrete.

@Ausraja,
Please do not spread wrong information to the forum, if you are not sure. Vibrator is NOT meant to be used just for the joints where the column, beam and slab meets. It is meant to be used in all the places where ever concrete is poured. This includes footings, columns, beams and slab.

[venkyn]

@civil88

Thanks for the suggestion. Your input has helped me to decide. My contractor is not using for columns so, was thinking seriously.

Also please share method to detect honeycombing at the early stage. Regarding the plasticizer, do we need to use it irrespective of usage of vibrator?

Thanks a lot.

Regards
Venky