Honey Combing at column toe
- Thread starter Valmiki
- Start date
Dnyan Deshmukh
Staff member
Pouring the concrete with pump, anything below 150 mm is like concrete gang is going to kill you.
Many folks do not have knowledge about the workablility of the concrete and thinks, slump above 150mm is dangerous for concrete.
But when you do concrete with slump less than 150mm which is pumped to a placing location, you will have lots of trouble in workmanship and finished product.
When we pour a concrete manually, the slump should be around 100 to 120mm because the placing rate is slow.
I too had observed many times, the honeycombing or aggregate exposed surface and the toe of column.
This happens due to moving of aggregates to one location during placing. Concrete placed from top need to reach at bottom through the cage of reinforcement.
This happens due to low fines at bottom which caused due to moving of aggregate after pouring. this can be avoided by placing 2 to 4 ghamela of cement mortar in proportion of 1:3 in each column base on size before pouring concrete into it
After concreting, those honeycomb need to be inspected by removing all loose material, if we found the honeycomb is in cover area, it can be patched straight a way.
If its going inside the core area i.e. concrete which is inside the cage of reinforcement shows honeycomb, the decision need to be taken base on severity observed in it. Up to some extent the column honeycomb can be rectified by patching it with concrete or micro concrete.
For honeycombing in concrete, a concrete mix design is also responsible, undersanded mix can cause large cavities in concrete. it is also better to get the mix design re-verified by doing trial at lab.
Many folks do not have knowledge about the workablility of the concrete and thinks, slump above 150mm is dangerous for concrete.
But when you do concrete with slump less than 150mm which is pumped to a placing location, you will have lots of trouble in workmanship and finished product.
When we pour a concrete manually, the slump should be around 100 to 120mm because the placing rate is slow.
I too had observed many times, the honeycombing or aggregate exposed surface and the toe of column.
This happens due to moving of aggregates to one location during placing. Concrete placed from top need to reach at bottom through the cage of reinforcement.
This happens due to low fines at bottom which caused due to moving of aggregate after pouring. this can be avoided by placing 2 to 4 ghamela of cement mortar in proportion of 1:3 in each column base on size before pouring concrete into it
After concreting, those honeycomb need to be inspected by removing all loose material, if we found the honeycomb is in cover area, it can be patched straight a way.
If its going inside the core area i.e. concrete which is inside the cage of reinforcement shows honeycomb, the decision need to be taken base on severity observed in it. Up to some extent the column honeycomb can be rectified by patching it with concrete or micro concrete.
For honeycombing in concrete, a concrete mix design is also responsible, undersanded mix can cause large cavities in concrete. it is also better to get the mix design re-verified by doing trial at lab.
Srinivasan
Prime CE
To avoid honeycomb in the toe of coloumns pour cement and sand grout 1:1for a thickness of 100 mm then pour concrete .you won't find any honeycombing in the toe of coloumns.purly a practical experience
civil kumar
Newbie
Santosh Chowdary
Newbie
Remove loose material and coarse aggregate of it comes and apply plastering in 1:3 or of the comb is too heavy put some concrete mixed with small C.A AND MAKE RRINFORCEMENT SURVIVE
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