Can I add gravel to a non shrink grout for pile head repair? 4

[redshot]

We are chipping concrete piles, as a result, cut concrete is more than 10 cm from the required level of pile head. Using non shrink grout without gravel is so expensive, so we need to add gravel because of extra thickness of concrete to repair. Can it be practical to add gravel? If so, what is the proportion of cement to gravel mix? Please any expert can give his opinion, is highly appreciated. tnx a lot.

 

[Ron]

Some grout manufacturers do not allow the use of coarse aggregate. Check with the manufacturer first.

 

[TXStructural]

I would use a proper concrete mix, rather than modifying a grout. Where a bagged product is labeled to be extended, use only the type and amount allowed.

 

[redshot]

Txtstructural,
thanks a lot for your excellent opinion. But our supplier provide us methods statement which recommend gravel as additional ingredient despite of manufacurer's specs that specifies only cement and water as grout mix.Because of extra cuts that ranges from 10-15 cm, the supplier recommends gravel with sizes about 5 to 10mm. Please explain further. thank you again.

 

[hokie66]

You should not accept a recommendation from a supplier which conflicts with the manufacturer's specification.

How are you preparing the pile heads? The appropriate way is to saw around the pile, then chip off the interior. If you are chipping without sawing, then in my opinion the piles will be unacceptable.

 

[TXStructural]

I hope you are not planning to use a neat grout (cement+water only) and get an acceptable, non-shrink grout. It will shrink to an extreme. If you mean to say "bagged, non-shrink grout", then you should not deviate from the label or manufacturer's instruction, or YOU are accepting liability when you do not get the required result.

Any reliable source (Sika, Ciba, etc.) will provide instructions for extending the material IF it is acceptable to do so. There are many good products which allow extending, and many more which do not. In short, if the grout is not designed to have aggregate mixed in, it probably does not bind well and provide strength when you do this. Also, consider the aggregate you propose to use, being sure it does not present an ASR or similar risk.

(And, please stop posting random documents which do not really explain or pertain to the actual job.)