Using pea rock concrete for grouting masonry

[slickdeals]

Folks,
Are there any problems with using a fluid pea rock concrete mix in lieu of grout for concrete masonry? Please let me know if there are any code issues in doing so? Is this okay once in a while or absolutely not?

 

[concretemasonry]

The specifications for grout aggregates are quite liberal. If you cannot meet the aggregate specifications, you have a problem.

The use of aggregate coarser than sand depends on the size of the grout spaces. The grout is not like concrete and must have a much higher slump to ensure full grouting and bond to rebars.

 

[henri2]

Pea gravel grout mixes are common and are considered coarse grout. There should not be too much problem provided the slump is between 9-11 in, mix is proportioned for workability, pumpability, strength etc and adequate clearances are maintained prior to grouting. Sika, Grace et al have great admixtures to enhance grout workability and pumpability.

Will you be proportioning/designing the grout mixture or reviewing it?

 

[spats]

What is the problem with specifying & supplying C476 grout? It's a simple "Betty Crocker" proportional mix, and then you know you've go the right stuff. Concrete suppliers more often than not have standard C476 mixes they can submit on demand.

Pea gravel concrete is not grout. What do you mean by "fluid"?... adding enough water to make it soupy? Not on my watch!

 

[slickdeals]

The problem is when the contractor requests to allow him to fill cells with concrete when there is one tie-beam to pour and the masonry wall to grout. I am only seeking opinions on what you have done in those circumstances.

 

[JKW05]

spats,

You must live in a good neighborhood. I can't tell you how many times I have received concrete mixes for grout mix submissions. I mean...low W/C, aggregates that are too large, A/E, superplasticizer to meet the slump.... These end up being 4, 5, 6000 psi mixes. I always insist on the basic C476 grout, but it usually takes pulling some teeth. Suppliers around here don't usually know what ASTM C476 is. And the masons around here won't acknowledge any difference between grout and concrete (they both just get hard).

 

[concretemasonry]

As Henri said, you need a high slump (9 to 11") for the grout (ASTM C476) to work. Adding water is not bad and is necessary for proper construction practices and to meet specificatons.

High strengths are not reaaly good and the grout should be approximately the strength of the masonry units to be grouted.

Spats, you better be prepared to add water. - This is grount placed in masonry units and NOT concrete that is placed in non-absorptive forms.

Also, if the stregth is checked, follow the ASTM C1019 procedure and do not use non-absorptive (steel, plastic, waxed, etc.) molds.

 

[spats]

In answer to slickdeal's inquiry of what do you do when the contractor requests to use pea gravel concrete, my answer would be to tell him NO!