Using Lime Waste as Hydraulically Bound Material in Sub-Base 1

[GJ1985]

I could do with some pointers on how lime waste (calcium sulfates & calcium chloride with various metals and some ash)could be used as a sub-base.

I'm looking to utilize the onsite lime waste product by either;

1. Treating the material to perform as an aggregate(crush and grade) within a hydraulically bound material
2. Incorporate directly with cement, although I'm not sure if this is permissible..

 

[fattdad]

two decades ago in Central Virginia, there was a company that brokered an engineering fill material that was made from flyash, bottom ash and lime kiln dust. It worked great! You could place and compact this in widely-varying moisture conditions and all seasons.

Then a new power plant came on line and the broker began commingling scrubber residue into the prior product. Now, the product included flyash, bottom ash, lime kiln dust and scrubber residue. That was a problem.

Bottom ash and flyash are basically unmineralized solids - like glass is unmineralized. This is not a problem, but for certain geochemical concerns. You see in the presence of lime kiln dust there was no issue. Sure, the environment was pH basic and the flyash was unmineralized, but it was stable.

Everything changed when the product began to include scrubber residue. The presence of sulfur (sulfide, sulfites, etc.) provided the missing link - and it was a bad link. Now in that same basic environment, we had all that was needed to form secondary minerals and that secondary mineralization caused great problems. You see, it resulted in the formation of ettringite and thomosite and those minerals (i.e., very prismatic) jacked up the building slabs and caused great structural damages! Entire retail stores were closed, demolished and reconstructed. A cottage industry developed from the Philadelphia attorneys and their lawsuits and counterclaims.

My advice? Never commingle such products with sulfur. Just don't do it!

f-d

ípapß gordo ainÆt no madre flaca!