The grout mix recommended for installation of ShapeArray is given in the table below. It is important to use bentonite powder for the mix since bentonite pellets will not incorporate well into the grout. The mix below results in a very soft grout which will minimize the influence of the grout on the soil displacement measurements. This is particularly important when installing ShapeArrays into large diameter boreholes in which the cross-sectional area of the grout will be large.

In cases where the ShapeArrays are installed in rock or concrete structures, it is possible to use a harder grout mix. Contact Measurand for more details.

Ratio by Weight

Portland Cement

43 kg



285 L


Bentonite Powder

+/- 18 kg*


 NOTE: Mix water and cement first. Then add bentonite powder, adjusting as required to get heavy cream consistency.

When mixing the grout, start by mixing the cement and water first. Do NOT mix the bentonite and water first, or you will not be able to mix the appropriate amount of cement into the grout, or the grout could flash set.

Once the cement and water are mixed, add in the bentonite. Mix the bentonite in a bit at a time until the grout mix resembles heavy cream. The consistency is very important, too watery a mix will result in shrinkage and segregation, too thick and it will not be possible to pump the grout.

NOTE: The grout mix given above is a guideline only. It is recommended that a grout mix be designed which will have similar strength and comportment as the soil in which the ShapeArray is being installed.