The Structural Formation of Cement Stone Modified by a Solution of Superabsorbent Polymer

With the development of 3D technologies in construction, the development of formulations that are indifferent to the influence of the environment is in demand. Conditions of intense water loss from cement systems arise during the layer-by-layer printing process. This leads to a decrease in density, high shrinkage, and a decrease in the strength and durability of the composite. The use of superabsorbent polymer (SAP) solutions, in contrast to granules, will provide hardening Portland cement with a water supply for internal care of hydration processes. The aim of the work is to study the effect of SAP solution on the processes of structure formation of cement stone, hardening in unfavorable conditions. In this paper, the features of the structure formation of cement systems in the presence of SAP are established. It is shown that the use of polymer in an amount of no more than 1.5% by the weight of Portland cement provides the formation of a more perfect crystalline structure of the cement stone, which allows for an increase in the degree of cement hydration. When the amount of SAP is ≥ 1.5% by the weight of Portland cement, a decrease in the intensity of the maxima corresponding to hydration products is observed.

Superabsorbent Polymer With Excellent Water/Salt Absorbency And Water Retention, And Fast Swelling Properties For Preventing Soil Water Evaporation

Superabsorbent polymers have important applications in many fields, but insufficiency of water/salt absorbency, water retention, and swelling rate limit its application development. Herein, we fabricated HEC-g-P (AA-co-AMPS)/laterite by aqueous solution polymerization, the structure and morphology of the superabsorbent polymer were characterized by FTIR, SEM and TG/DTG. The optimal water absorbency of the superabsorbent polymer were 1294 g/g, 177 g/g, and 119 g/g in distilled water, tap water, and 0.9 wt% NaCl solution, respectively. The superabsorbent polymer had good water retention and re-swelling properties at different temperatures, and fast water absorption rate, and reached swelling equilibrium at 5 min. The swelling mechanism of the superabsorbent polymer was explained by the pseudo-second-order swelling kinetics model and Ritger-Peppas model. The effect of the amount of hydrogel on the water evaporation rate in soil was studied, and it had a good effect.