A Research on Durability Degradation of Mineral Admixture Concrete.

In order to study the degradation laws and mechanisms of admixture concretes with single-added SO and composite of Mg and SO, respectively, the durability tests were conducted on three types of mineral admixture concretes (concretes with single-added metakaolin (MK), single-added ultra-fine fly ash (UFA), and composite of metakaolin and ultra-fine fly ash (MF), and one reference concrete. In these tests, the 10% NaSO solution and the 10% MgSO solution were used as the erosion medium, and the drying-wetting circle method was applied. It can be seen from the compressive tests and grey relational analysis that the MK admixture can improve the anti-NaSO-erosion capability of the concrete significantly, but weaken its anti-MgSO-erosion capability; the UFA admixture can improve both the anti-NaSO-erosion and the anti-MgSO-erosion capability of the concrete; and the composite admixture has superimposed effects and can enhance erosion resistance against these two erosion mediums.