THE INFLUENCE OF THE TYPE OF LOW-EMISSION CEMENT AND AIR-ENTRAINING ADMIXTURES ON THE QUALITY OF AIR ENTRAINMENT OF CONCRETE – UNEXPECTED IMPACT OF GRANULATED BLAST FURNACE SLAG

The test results indicate that it is possible to obtain the appropriate quality of air entrainment in concrete with lowemission cement with granulated blast furnace slag, such as CEM II/B-S, CEM III/A and CEM III/A-NA. However, the literature on the subject reports that this is not the rule, and a slag content that is too high is not conducive to the effectiveness of the air-entraining admixture and the stability of the air entrainment. The possible reason for the beneficial effect of slag on the stability of air entrainment was the influence of surfactants used for its grinding. The research also proved that the effectiveness of the air-entraining impact and the stability of air entrainment in concrete with slag cement depend on its type (natural or synthetic) and the alkali content in the cement.