Effects of Functional Chelator and Mineral Admixture on the Salt Freeze-Thaw Resistance of Cement-Based Materials

Abstract

The effects of functional chelator and mineral admixture on the salt freeze-thaw (F-T) resistance of cement-based materials were investigated. The salt F-T resistance of mortar was evaluated by mass loss, compressive strength loss and total porosity change. The results indicated that the properties of mortar with functional chelator are significantly superior to those of ordinary mortar after the salt F-T cycle test. Compared with the ordinary mortar, after 100 salt F-T cycles, the mass loss and the compressive strength loss of the mortar with 0.5% functional chelator were reduced by 23.6 and 26.7%, respectively. Moreover, the salt F-T resistance of the mortar with functional chelator and mineral admixtures was further promoted. As for mortar with 0.5% functional chelator and 20% slag grinding, the mass loss and the compressive strength were reduced by 24 and 11.3% than the mortar only with 0.5% functional chelator after 100 salt F-T cycles. Meanwhile, the total porosity of the mortar with 0.5% functional chelator and 20% fly ash was 24.3% less than the mortar only with 0.5% functional chelator after 100 salt F-T cycles. According to the SEM analysis, the mineral admixtures could fill the pores of the mortar, and the functional chelator could repair the crack of mortar after salt F-T cycles.