Influence of storage time on the properties of controlled hydration mortars

Abstract

The incorporation of hydroxycarboxylic acid salts and carbohydrates enables the production of controlled hydration mortars (CHMs), in which the control of the induction period allows handling of the material for extended periods. Despite the widespread use of this material in Brazilian construction, the significant incompatibility between plant and laboratory production methods limits the establishment of normative parameters and consistent evaluation criteria for these mortars. Therefore, this study aimed to evaluate the influence of storage time on the physical properties of plant-produced CHMs. From the analysis of fresh state properties, it was observed that several compositional and workability parameters are statistically affected by the storage time of the mortars. Moreover, calorimetric evaluations revealed a marked discrepancy between the setting time, the shelf life, and the handling period of this material. In the hardened state, the dynamic modulus of elasticity and the mechanical strengths of the mortars also exhibited statistically significant variations as a function of storage time; however, bond strength and capillary water absorption coefficients did not. Finally, it is highlighted that the correlation of properties across different physical states contributes to identifying key parameters for controlling the performance of CHMs.