net ▁( see ▁first ▁bullet ▁point ▁above ). ▁This ▁can ▁be ▁represented ▁per ▁the ▁following ▁equation : ▁▁ 3 C 2 A H 8      →      2 C 3 A H 6    +    A H 3    +    9 H      ( cement ▁chem ist ▁notation ) ▁▁ ▁Per ▁the ▁first ▁bullet ▁point , ▁although ▁the ▁inclusion ▁of ▁calci um ▁al umin ium ▁gar net ▁per ▁se ▁is ▁not ▁problem atic , ▁if ▁it ▁is ▁instead ▁produced ▁by ▁for ego ing ▁path way , ▁then ▁micro - c rack ing ▁and ▁strength - loss ▁can ▁occur ▁in ▁the ▁concrete . ▁ ▁However , ▁adding ▁high - react ivity ▁po zz ol ans ▁into ▁the ▁concrete ▁mix ▁prevents ▁such ▁a ▁conversion ▁reaction . ▁In ▁sum , ▁whereas ▁po zz ol ans ▁provide ▁a ▁number ▁of ▁chemical ▁path ways ▁to ▁form ▁hard ened ▁materials , ▁" high - react ivity " ▁po zz ol ans ▁such ▁as ▁bl ast ▁furn ace ▁sl ag ▁( G GB FS ) ▁can ▁also ▁stabil ise ▁certain ▁path ways . ▁In ▁this ▁context , ▁E MC s ▁made ▁from ▁fly ▁ash ▁have ▁been ▁demonstrated ▁to ▁produce ▁con cre tes ▁that ▁meet ▁the ▁same ▁characteristics ▁as ▁con cre tes ▁compr ising ▁" 1 2 0 ▁S lag " ▁( i . e ., ▁G GB FS ) ▁according ▁to ▁U . S . ▁standard ▁A ST M ▁C 9 8 9 . ▁ ▁Port land ite , ▁when ▁exposed ▁to ▁low ▁temper atures , ▁mo ist