Grouting a Random Rubble Stone Basement Wall 2

[cap4000]

I am looking for the best way to grout a basement rock wall. I am proposing a plywood form braced to the slab and 1/2 inch off the wall. I am specifing a high strength fluid flowing Vexcon or Sika grout to be poured in over the top of a seven foot high form. Hopefully by hammer tapping the plywood it will fill all the voids in the stone wall. Currently the 90 year old wall has no mortar and must be underpinned. Has anyone ever used pressure injected grout or gunite in a wall like this. Any other suggestions will be appreciated.

 

[civilperson]

Use mortar tight forms and a threaded nozzle entrance at the bottom with visible relief tube out of the top. Pump a small aggregate concrete or grout while using a vibrator against the forms to consolidate mix.

 

[cap4000]

Thanks for the quick response. This basement however is completely enclosed with no windows. Can you describe your bottom up pumping system a litte further.

 

[concretemasonry]

Look into either self consolidating concrete (SCC) or self consolidating grout (SCG). The need for vibration is eliminated because of the unique properties of the admixtures. Both BASF and Lafarge have been active in the reaseach and approval proces.

There is extensive development in the code acceptance of SCG) and project applications for the grout by the National Concrete Masonry Association (NCMA) and the admixture suppliers. The grout is intended for concrete masonry where the excess water is benficial and can be handled by the absorption by the units. The thrust of the development is to provide a method of high lift grouting without the associated problems created by successive lower lifts. The ability to provide quality grout without the bridging you may encounter with the 1/2" clearance may provide an option.

The SCC may be more applicable to your situation since your wall MAY have low absorption, but the aggregate size used in the testing may limit applications. The National Ready Mix Concrete Association (NRMCA) has information.

These products may fit into your project and provide pouring from the top.

 

[cap4000]

Thanks for the SCC tip. The Vescon or Sika sand/grout f'c strengths are on the order of 8 to 10 ksi in a fluid application. Once the wall is stripped they will be furred out and finished with sheetrock.

 

[PEinc]

Did you ask a masonry comtractor if it is possible to mortar the open joints? You might be surprised by his answer and his price.

 

[cap4000]

PEinc

I am really specifing a "Structural Grout Job" for future underpinning work all to be done by a Concrete Contractor.