Destruction of mortars and concrete through the crystallization of water in the pores  depend on  the  amount  of  water  that is incorporated in the cement matrix.

Through the smaller pore obtained by the use of metakaolin, the water uptake can be reduced. Concretes produced with metakaolin show an increased freeze-thaw resistance if low w/b ratios* are used.


* w/b ratio - water to binder ratio