Expanding Hydrogel Aggregate for Self-Compacting Products

Abstract

Hydrogel spheres made of sodium polyacrylate with free absorption of water can increase in volume by 100-1000 times due to the violation of the balance of forces of attraction and repulsion between the links of the gel. The addition of water will shift the balance in favor of the repulsive forces. This property will allow them to be used in cement systems as an active expanding aggregate, which will compact the structure, reduce the water-cement ratio during the formation of the cement paste structure, and then give water to the hardening cement stone. The hydrogel sphere itself will decrease in volume to its initial state and will leave the pore in its place. The resulting material can be considered aerated concrete with compacted inter-pore partitions. The advantage of this method over the traditional method of self-compacting masses is that there is no need to supply thermal energy to activate the expansion of the active aggregate, for example, by passing an electric current through the hardening mass. In this article, the properties of the hydrogel are investigated, the dynamics of the expansion of hydrogel spheres in water at different temperatures is determined.