Effect of permeability reducing admixtures on fresh and hardened state properties of cementitious systems containing mineral admixture

In this study, the effect of utilization of the permeability reducing admixture (PRA) with different effect mechanisms on fresh and hardened state properties of cementitious systems containing mineral admixtures was investigated. For this purpose, 3 commercial PRA admixtures provided from 2 different companies were used. The effective parameters in 1th and 3th admixtures are declared by the manufacturers as air entraining and high-rate of air entraining properties, respectively. According to the manufacturer the second admixture contains the insoluble residue and have low-rate of air-entraining property. Cement paste and mortar mixtures having binary and ternary cementitious systems were produced by partially replacement of cement with fly ash and metakaolin. Marsh-funnel flow time and mini-slump behavior of the cement paste mixtures were investigated. In the mortar mixtures, fresh state properties such as air content and time-dependent flow values and hardened state properties such as compressive strength, water absorption, ultrasonic pulse velocity, freeze-thaw resistance and drying-shrinkage behavior were examined. The mixture having ternary cementitious system containing both fly ash and metakaolin was chosen as the most successful mineral admixture-bearing mixtures in terms of the hardened state properties. In this context, among the permeability reducing admixtures-bearing mixtures, the mixture containing PRA admixture both containing insoluble residues and having small amount of air-entraining properties exhibited the best performance. Combined using of mineral and permeability reducing admixtures had a more positive effect on the properties of the mixtures.