Abstract
The article presents studies of the effect of a complex modified additive on the setting time of cement paste. The work describes the method of determining the setting time of the cement paste of standard consistency, the selection of the optimal composition of the additive at different percentages of its components, allowing accelerating the setting time. In this work, the authors used a complex modified additive including alkali (caustic soda NaOH), post-alcohol bard (alcohol production waste), and hardening accelerator (gypsum) in different percentages. Performed a comparative study of the effect of additives on changes in setting time. The analysis suggests that the additive in the optimal amount leads to changes in the setting time compared with the reference sample, but within the standards. It is shown that the combined use in the composition of a complex modified additive, having well-compatible mechanisms of their influence on the processes of hydration, setting, and hardening of the cement paste, mutually complements and enhances the effect of each ingredient of the additive. Increasing the concentration of the complex modified additive in the cement paste not only affects the liquefaction process but also reduces the setting time and hardening of the cement paste.