Chemistry Cement materials can be classified into two distinct categories: hydraulic cements and non-hydraulic cements according to their respective setting and hardening mechanisms. Hydraulic cement setting and hardening involves hydration reactions and therefore requires water, while non-hydraulic cements only react with a gas and can directly set under air.
CHemisTrY CemEnt mAtErials can Be cLAsSified iNTo two distinct categoRies HyDrauLIc cemENts anD noN-hYdraulIC CEments ACCorDing to their rEsPectIvE setTing And haRdEning mEChAniSMS. hyDraUlic Cement Setting aNd haRdeninG inVolVes hyDrAtion ReacTiOnS anD THerEfore requiRes wateR, WhIle non-hydraulic ceMEnTs ONly rEAct with A gAS And can DIrecTly sEt under air.