Make non-shrink grout from portland cement

[John_G]

Hi,

is there a way to make a non-shrink grout from ordinary portland cement (by adding anything to it)?


Thanks.

 

[hokie66]

Portland Cement is one component of non-shrink grout, so the answer is yes, but the other components is the problem. The formulas are tightly held proprietary information.

 

[Ron]

hokie66 is correct as usual! There are additives that react with portland cement that cause expansion to counteract the inherent shrinkage during the hydration of portland cement. Aluminum powder is one of those additives, but the proportions have to be carefully controlled. Another way to reduce shrinkage is to use an aggregate that has low absorption such as metallic aggregates and some slag aggregates...again the 'recipe' is critical which is why, as hokie66 noted, the manufacturers guard their secrets of the mix.

 

[JedClampett]

There are admixtures (Grace Eclipse) that, if you look at their behavior, simulate a non-shrink grout (slight early expansion, with the shrinkage happening later). But I don't think they're as pronounced as non shrink grout.
You can call W. R. Grace and I guarantee you'll have a friend for life.

 

[epoxybot]

I think the application would define if a field mix was feasible. If you are looking for flowable non-shrink grout then you are best advised to stick with premium brands. If you are damp-packing the base plates of light standards, you could probably come up with a OPC mortar. If you are just looking to see what might be possible then a blend of OPC & Hydraulic Cement might be a place to start.
Open up a bag of non-shrink grout and you might be surprised at the larger sand fractions. A lot of effort goes into sourcing the various sand fractions used in making the premium grouts.