Interior Sandblasting / Contamination

[tincan]

I have an interior basement where the walls and columns have severe spall/fracture due to salt contamination/rusting of the re-bar in the walls and the WF's in the columns. The concrete covering for the WF columns are fire protection and have no structural capacity.
The walls are fillers, no loading either side (exterior face is a dry-well, or top (the floor loading is carried by a WF beam between the WF columns. The basement area is highly utilized, mechanical area for the bldg.

I need to remove the spalled/deteriorated concrete and clean the re-bar and WF's and then reface/resurface the items. Contamination from sandblasting must be confined to the immediate area and kept out of the mechanical areas. Have done rehab work outside but not inside.

My question. Can contamination barriers be used with sufficient success to prevent dusting of the basement area? Any other suggestions?

Thanks, Tincan.

 

[SlideRuleEra]

tincan - Perhaps you can consider high-pressure water blasting. I have seen this used in the basements of electric power generating stations - these basements do have the advantage of being constructed with trenches, sumps, etc. to handle the "used" water.
Here is a typical link for information:

http://www.nlbcorp.com/water_blasting_concrete_cutting.html

 

[Ron]

tincan...consider using dry ice as your blast media. It evaporates to nothing and the only residue you have is the material blasted.

 

[jheidt2543]

Sandblasting has become very regulated by OSHA because of the potential effects of sand and concrete dust getting into the lungs and causing silicosis. There are specialty contractors that do this work, they have the protective equipment etc., you might contact one of them for a price and compare it to the other suggestions.

 

[JAE]

I just finished a project almost exactly like this - they used shot instead of sand and did put up plastic barriers framed in wood to keep the dust under control. This was a garage rehab project under a multi-story building.

 

[StephenA]

Sandblasting has now been replaced by gritblasting (due to silicosis as jheidt2543 says) and there are various combinations for different uses. Copper slag is one I think.

Water blasting can also use grit to assist.

Ask your local grit blasting company

StephenA

 

[dbuzz]

Another alternative worth consideration is sponge blasting.

http://www.spongejet.com/

 

[elpoblano]

Tincan,

To use sandblasting, you also need to check the environmental regulations in your area. Those regulations should also have a guideline for permissible techniques to use in selective demolition or restoration. It will save you substantial time and unnecessary effort. I agree that hydroblasting is a more environment frienly demolition process. The problem are the nozzles used and the residual water generated. The nozzless need to rated to maximum pressure rate and the hydroblasting company should take care of it. About the residual water, Can the hydroblasting company collect it? Does your basement has a sump where to collect it? Does your community permits direct disposal on the sewer system?

Dry ice in my experience it did not work for concrete demolition. We use it for cleaning concrete surfaces only. Yes, it does evaporate in the air; the residual debris comes from what is removed from the material being cleaned.

The pressures that have given us excellent results removing the deteriorated concrete without damaging the sound substrate vary from 8,000~15,000 psi. We do a lot of concrete vessels restoration.

 

[tincan]

Thanks for the input. Its appreciates.
Tincan.