Answered Why honeycombing came in column

Dnyan Deshmukh

Eternal Member
Staff member
Sep 7, 2017
2,632
4,580
Pune
There are many reasons due to which, honeycombing occurs in concrete.

Particularly about your issue.

- gaps at shutter at bottom shows slurry loss and small honey combing.

- Mix look like do not have proper workability (If you are using one bag mixer to produce a concrete, then variation may be occurred in each batch, if not using water dispenser for pouring water in mix)

- If you are using RMC / or doing batching with one bag mixer.

there may be a gap in concrete occurred due to
vibrator was not working
labour gone for lunch
or some other issue which stopped the concreting activity for sometime.

This are the basic issue which may happens and concrete get spoiled.

Now Come to a structural issue

- column looks like heavily reinforced
There is a possibility that, concrete have low workability and the vibrator cant go inside properly due to heavy reinforcement and due to improper or no compaction this issue get arise.

Remedy

- the easiest and cost saving remedy is to break the column and recast (if you can see through the honey comb or water passes from one end to another) Its not good to rectify cavity in compression member.

- You can rectify such pockets either by doing a self compacting concrete or micro concrete inside it (This is costly and not recommend, If the structure above is already built and later we came to know about such pockets, we can do this instead of breaking whole structure).

To avoid such issue in future you can implement following

- Redesign the mix with required parameters like workability, retention time etc.
- Ask your structural consultant to do some changes in design, if you cant compact concrete by inserting needle.
- Ensure vibrator needle is having sufficient length for insertion.
- Do keep backup alternative like vibrator which have diesel engine, to ensure compaction during no electricity or failure of electricity supply.
- In case of bag mixer, use electrically operated water dispenser which dispense the amount of water which we set.
- Ensure all working platform, material, manpower and machinery required for concrete are available before starting concrete (after starting concrete if you search for vibrator or any other equipment/ manpower, it will cause some issue in concrete)

Enjoy happy concreting by taking care of above points :)
 

Harikiran N

Staff member
Sep 7, 2017
35
24
Bengaluru
Reasons;
Lack of compaction.
Lack of workability i mean slump level.
Use concrete after 180min , after i loosen the ptoperties.
Also chances of gap in formwork...
Also using high size of downgrade matetials.
 

Shubham Gomare

Junior Member
Mar 1, 2018
27
22
Pune
There are many reasons due to which, honeycombing occurs in concrete.

Particularly about your issue.

- gaps at shutter at bottom shows slurry loss and small honey combing.

- Mix look like do not have proper workability (If you are using one bag mixer to produce a concrete, then variation may be occurred in each batch, if not using water dispenser for pouring water in mix)

- If you are using RMC / or doing batching with one bag mixer.

there may be a gap in concrete occurred due to
vibrator was not working
labour gone for lunch
or some other issue which stopped the concreting activity for sometime.

This are the basic issue which may happens and concrete get spoiled.

Now Come to a structural issue

- column looks like heavily reinforced
There is a possibility that, concrete have low workability and the vibrator cant go inside properly due to heavy reinforcement and due to improper or no compaction this issue get arise.

Remedy

- the easiest and cost saving remedy is to break the column and recast (if you can see through the honey comb or water passes from one end to another) Its not good to rectify cavity in compression member.

- You can rectify such pockets either by doing a self compacting concrete or micro concrete inside it (This is costly and not recommend, If the structure above is already built and later we came to know about such pockets, we can do this instead of breaking whole structure).

To avoid such issue in future you can implement following

- Redesign the mix with required parameters like workability, retention time etc.
- Ask your structural consultant to do some changes in design, if you cant compact concrete by inserting needle.
- Ensure vibrator needle is having sufficient length for insertion.
- Do keep backup alternative like vibrator which have diesel engine, to ensure compaction during no electricity or failure of electricity supply.
- In case of bag mixer, use electrically operated water dispenser which dispense the amount of water which we set.
- Ensure all working platform, material, manpower and machinery required for concrete are available before starting concrete (after starting concrete if you search for vibrator or any other equipment/ manpower, it will cause some issue in concrete)

Enjoy happy concreting by taking care of above points :)
There are many reasons due to which, honeycombing occurs in concrete.

Particularly about your issue.

- gaps at shutter at bottom shows slurry loss and small honey combing.

- Mix look like do not have proper workability (If you are using one bag mixer to produce a concrete, then variation may be occurred in each batch, if not using water dispenser for pouring water in mix)

- If you are using RMC / or doing batching with one bag mixer.

there may be a gap in concrete occurred due to
vibrator was not working
labour gone for lunch
or some other issue which stopped the concreting activity for sometime.

This are the basic issue which may happens and concrete get spoiled.

Now Come to a structural issue

- column looks like heavily reinforced
There is a possibility that, concrete have low workability and the vibrator cant go inside properly due to heavy reinforcement and due to improper or no compaction this issue get arise.

Remedy

- the easiest and cost saving remedy is to break the column and recast (if you can see through the honey comb or water passes from one end to another) Its not good to rectify cavity in compression member.

- You can rectify such pockets either by doing a self compacting concrete or micro concrete inside it (This is costly and not recommend, If the structure above is already built and later we came to know about such pockets, we can do this instead of breaking whole structure).

To avoid such issue in future you can implement following

- Redesign the mix with required parameters like workability, retention time etc.
- Ask your structural consultant to do some changes in design, if you cant compact concrete by inserting needle.
- Ensure vibrator needle is having sufficient length for insertion.
- Do keep backup alternative like vibrator which have diesel engine, to ensure compaction during no electricity or failure of electricity supply.
- In case of bag mixer, use electrically operated water dispenser which dispense the amount of water which we set.
- Ensure all working platform, material, manpower and machinery required for concrete are available before starting concrete (after starting concrete if you search for vibrator or any other equipment/ manpower, it will cause some issue in concrete)

Enjoy happy concreting by taking care of above points :)

Sir,
Can you please explain the treatment of honeycombing in detail
 

amd007

Premium Member
Apr 17, 2018
229
317
mumbai
View attachment 102

Can anyone tell me, why honeycombing occured here.

What are the remedy for correcting it
Our Dear Dynan Deshmukh as addressed all the possible methods for honeycombing and its treatment.

However, if we were to talk only about this particular incident as shown in the photo then my views are as below:
  1. Work is being done by totally unqualified people. Only dumb people can do such poor quality work not a work of a qualified engineer.
  2. No safety shoes being used by workers
  3. No safety helmet
  4. Plinth work like soling, pcc should have been completed before casting of the column, here you can see totally (gav khate ka kam chalu hai )
  5. See the props below the beam bottom in the backdrop totally slanting when it should be upright
  6. This honeycomb has occured basically due to stiff concrete mix and no vibrators used for compaction
  7. Plus if you see the bottom of the column there is no proper gap filling done at the foot of the column
  8. Cover is also missing which is evident from the stirrups which are seen in the concrete layers.
  9. Curing being done by hessian cloth but not a single drop of water seen in the picture.
  10. Column steel should alternately staggered which is also missing plus lap length seems inadequate for the short bars seen in the photo.
  11. As regards to the rectification for such kind of honeycombs is BREAK THE TOTAL COLUMN AND CAST NEW ONE. There is no other alternative for a compression member.
 

Jayant Joshi

Premium Member
Mar 15, 2018
84
55
Valsad
I think this is not honeycomb or even voids.
We have to give some another name for such condition.

This is mainly due to negligence of site engineer.
Dense concrete. Low water cement ratio.
No vibrator.
Loose shuttering.
Oversized aggregates.
Pouring concrete from height.
Time gap between two pouring etc etc etc.

All the good RCC practices are viloted.

Remedy is
Break the entire column in presence of all who has worked on this column.
Site engineer must be issued notice or should be sacked out from site.