Specifying Light Sandblast Concrete Finish
Specifying Light Sandblast Concrete Finish
(OP)
What is the proper technical description to include in a project specification for a light sandblast finish?
In a preliminary architectural finishing specification prepared by the architect for the project, that we (structural engineers) are reviewing, it describes the following (see below) for a "light sandblast finish". Is that an acceptable description for a light sandblast finis? I would have thought that a light sandblast finish would expose the fine aggregate, but not the coarse aggregate.
"After concrete is 21 days old and thoroughly cured, sandblast using a hard sharp sand until course aggregate is in uniform relief and light texture is achieved to match approved mockup sample".
In a preliminary architectural finishing specification prepared by the architect for the project, that we (structural engineers) are reviewing, it describes the following (see below) for a "light sandblast finish". Is that an acceptable description for a light sandblast finis? I would have thought that a light sandblast finish would expose the fine aggregate, but not the coarse aggregate.
"After concrete is 21 days old and thoroughly cured, sandblast using a hard sharp sand until course aggregate is in uniform relief and light texture is achieved to match approved mockup sample".






RE: Specifying Light Sandblast Concrete Finish
http://www.caltrain.com/assets/_engineering/engine...
BA
RE: Specifying Light Sandblast Concrete Finish
RE: Specifying Light Sandblast Concrete Finish
RE: Specifying Light Sandblast Concrete Finish
RE: Specifying Light Sandblast Concrete Finish
Sorry, I can't say whether the spec I referenced is accepted by the various standards you mentioned, but I agree with hokie66 that test panels are the best way to ensure the architect is happy with the resulting finish.
BA
RE: Specifying Light Sandblast Concrete Finish
Dik
RE: Specifying Light Sandblast Concrete Finish
Thanks everyone for the helpful comments. Particularly to BARetired for the document.
RE: Specifying Light Sandblast Concrete Finish
RE: Specifying Light Sandblast Concrete Finish
Also, you cannot reasonably expose the fine aggregate without also exposing coarse aggregate. "Light" sandblast is related to depth of relief. The goal is to mechanically etch the surface paste for slight texture and uniformity.
RE: Specifying Light Sandblast Concrete Finish
As Ron and Hokie have noted, sandblasting brings out imperfections, too. These can be minimised by proper reinforcing, curing and jointing.
Dik
RE: Specifying Light Sandblast Concrete Finish
Hokie66, you being in Australia, perhaps do not have the same range of thermal cycling and resulting concrete cracking as we do here in this part of Canada (if my memory is right, we had this discussion about a year or 2 ago!).
RE: Specifying Light Sandblast Concrete Finish
RE: Specifying Light Sandblast Concrete Finish
RE: Specifying Light Sandblast Concrete Finish
RE: Specifying Light Sandblast Concrete Finish
As an aside regarding the mock up... include features that will be in the final structure, ie. elec outlets, returns, corners. It's also essential, in my opinion, to have a site superintendent who is on board and invested in providing the craftsmanship to make the final product
meetapproachapproximate the architect's vision.RE: Specifying Light Sandblast Concrete Finish