Influence of the combined action of admixtures, air entraining and hydration stabilizing, on the properties of the stabilized mortar for up to 48 hours

ABSTRACT

The stabilized mortar feature is an extended setting time. The use of air-entraining admixture and hydration control admixtures are essential to maintain the fresh stage of the mortar on site and with adequate workability. This paper analysed the combined influence of these additives, aiming to contribute to the mortar dosage. Nine formulations were tested, which varied the content of additives, between the maximum and the minimum recommended by the manufacturer. The tests in the fresh stage were: consistence index, specific gravity and air entrained content and Squeeze-flow; and in the hardened stage were: flexural and the compressive strength and tensile bond strength. The efficiency of the additives in maintaining the rheological properties of the mortars, keeping them workable, was verified, but a loss of mechanical properties in the solid stage was also identified, due to hydration problems due to excess hydration control admixtures and the formation of voids by use of air-entraining admixture. Thus, it is concluded about the importance of compatibility between admixtures together and technological control in the dosage of mortars, so that they remain workable without losing the mechanical properties necessary for good performance and durability.

Keywords
stabilized mortar; air entrainer admixtures; hydration stabilizer admixtures