Does anyone out there have insights on the polishability (is that a word?) of concrete mixes with low cement content or high supplementary cementitious materials? Dave Walsh with Sellen gave some good insight into this and how both of the above can cause rock popping during the grinding/polishing process. There seems to be an interesting dance between embodied carbon and polished concrete finish.
1 Like
Same question re: type 1L cement, aggregate size, w/c ratio, or anything else you might find in a slab mix design.
I don’t think that either SCMs or use of Type IL should affect the performance of concrete with respect to polishing, staining, etching, or any other type of finish that may be applied to concrete. If a producer is aware of what is intended for the concrete, they should work with the contractor to ensure the mix design takes into account the intent for the finish. This may also include if moisture sensitive floor coverings are to be used.
All of that said, I do know that some producers of surface finishes may have restrictions and limits on specific materials that can be used in concrete because of how they interact with their materials which may include polishing aids, surface hardeners etc. Anyone considering using such materials should work with the manufacturer, concrete producer, GC, and polishing contractor to ensure that the materials and systems are compatible.
1 Like
Popping aggregate could be caused by a Chert aggregate which is a rock that expands during the concrete curing process. As the concrete shrinks the aggregate is compressed and pops. Chert is present in aggregates in different parts of the USA. Using recycled concrete would make it difficult to eliminate from a finished surface.