Optimal concentration of post-alcohol bard and microsilica in cement-sand mixtures determination

Abstract

The article presents part of the results of the study of the components of foam concrete made by the two-stage foam injection method, in particular, the influence of microsilica and post-alcohol bard on the setting time and strength of cement. The paper shows the methodology for determining the compressive and flexural strength, selection of the composition of components, analysis, and evaluation of setting times, and strength characteristics of the compared samples. During the study, laboratory experiments were performed to better understand how these additives affect the behavior of cement mixtures. The studies carried out allow us to determine the influence of the modified additive components on the properties of foamed concrete during the production process. The setting time analysis presented in the study revealed that increasing the concentration of the additive significantly reduced the setting time performance of cement. With increasing the content of microsilica and post-alcohol bard at 10% and 30% of the cement weight, the setting initiation and completion times are significantly reduced. To evaluate the change in strength, samples were made and tested in compression and flexure at ages of 3, 7, 14, 21, and 28 days of normal moisture curing. According to the results, it was found that the additive, by accelerating the curing, promotes strength improvement both at an early age and at the design age (28 days). The experimental results showed that the flexural and compressive strength of the material increased as the concentration of the additive increased. The maximum increase in flexural and compressive strength was recorded at additive concentrations of 10% and 30%. This indicates the important role of additives in the strengthening of materials and their potential application in construction. The additive showed an optimum positive effect, therefore, the use of this percentage of additive is the most effective for increasing the compressive and flexural strength of concrete.