Freeze‐thaw resistance of concretes with low‐clinker cements

The effective use of low‐clinker cements in concrete applied in a climate with freeze‐thaw cycles is a major challenge in terms of frost durability. One of the main factors affecting the frost resistance of concrete is proper air entrainment. The use of new cement types requires constant improvement of the process of air entrainment of the concrete mix, because the application of new components to their composition significantly affect the effect of air‐entraining admixtures. This forces constant control of the effectiveness of concrete air entrainment.

The article compares the possibilities of shaping the frost resistance of low‐clinker concretes with the use of polymer microspheres and traditional air‐entraining admixtures. In the tests ternary low‐clinker cements (≤ 65% of Portland clinker) made with non‐clinker main components such as silica fly ash (V), ground granulated blast furnace slag (S) and limestone (LL) were used.

On the basis of the conducted tests, it was found that polymer microspheres ensure greater repeatability in shaping the correct air‐entrainment structure of low‐clinker concretes compared to traditional air‐entraining admixtures and cause a smaller decrease in compressive strength, while ensuring a high degree of frost resistance in water.