Structural fill can be multiple things.  Sometimes it is just screened soil without large rocks or it can be foundry sand (basically sand) or other forms of material that has better properties than native soil to firm up around foundations.  Crusher fines are recommended for paddocks.  I'd just make sure that the structural fill is really crusher fines and not just screened soil.  The binders are most likely something like clay to help hold the fines in place and compact.  I would ask to see the material and ask specifically what the binder is, is it clay or a chemical and what that chemical is.

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