I seriously doubt you'll find "limecrete" as a ready made product, but the lime you want (which you can then mix aggregate into) is "Mason's Lime" - unless you are abnormally brave and silly and want to risk playing with quicklime, which is VERY nasty stuff. Type S or SA (air-entraining - makes small bubbles which help various properties of the product) are probably what you want, and will be able to find at any well-stocked masonry supply.
From the second link below:
Hydrated limes used in building applications are divided into four
types, as described in ASTM Standard Specification C 207 (Hydrated
Lime for Masonry Purposes): Type N – normal hydrated lime Type NA –
normal air-entraining hydrated lime Type S – special hydrated lime
Type SA – special air-entraining hydrated lime Types S and SA are
differentiated from Types N and NA principally by the unhydrated oxide
content and their water retention value. Type S must meet a water
retention value of 85%, while Type N hydrate lime must have a water
retention value of 75%. No distinction is made based on the nature and
source of limestone. The maximum air content of cement-lime mortar
made with Types NA and SA is 14%; with Types N or S lime, 7%.
Type s and sa mason's lime described.
National Lime Association
More about type S