Mechanical properties and durability of lime mortar using aggregate made from phosphogypsum and steel mill slag

The present investigation deals with the utilization of phosphogypsum and steel mill slag combined with lime and raw bentonite as a cementitious material used for road construction and durability of mortar.
The result reveals that the stabilization of bentonite by lime enhances mechanical strength of the material, mainly due to the alkaline environment promoting the formation of aluminates and silicates found in Portland cement. Additionally, the addition of phosphogypsum increases the compressive strength by 7 times, with an increase of 20% compared to lime-bentonite aggregate. This is partially due to stratlingite formation, obtained by reaction of CAH10 with C-S-H. The steel mill slag further increases this compressive strength by 10 times, because the occurrence of dicalcium silicate and metal flakes.