"[A]fter 7 days of curing, the concrete without SF attained approximately 65%–80% of [compressive] strength at 28-day[s]... the specimens encompassing SF gained approximately 80%–95%... [I]n FC without SF, the 90-day strength was approximately 75%–90% of the conforming... strength. [S]pecimens encompassing SF gained around 80%–95% of the equivalent 90-day strength. Therefore, the FC with FA can gain strength over a long period."