Water-repellency treatment of mortars by using additives based on polymer residue
Polymeric residue of sulfate pulping, which is a mixture of high-boiling terpene and terpene compounds, has been investigated as a modifier of properties of mortars. Water-repelling ability of the polymer residue has been confirmed. Technology for producing additives in dry mixes has been developed by emulsifying a polymer residue in water and mixing the emulsion with a hydrophilic powder followed by drying the emulsion. For the technology developed, the ration for the components of the emulsion has been chosen and water-repelling additive based on fly ash and polymeric residue has been obtained. By using the method of the planned experiment, model composition of the mortar of low water absorption, which includes developed additive superplasticizer C-3 and hardening accelerator - calcium formiate have been optimized. For the technology developed matched ratios of the components of the emulsion and produced hydrophobic additive based on fly ash and polymer residue. By the method of the design of experiments optimized model composition of mortar of reduced water absorption comprising an additive designed, С-3 superplasticizer and hardening accelerator calcium formiate. With the software package STATISTICA 6.1 regression equations have been gained with confidence of about 0.95, describing the dependence of water demand, water absorption, coefficient of water saturation and compressive strengths of the mortar from the consumption of additives. Analysis has been performed for equations and charts based on them and indicating a decrease in water absorption more than twice under using water-repelling additive in an amount of 2.5% or more from the cement weight. Side-effects such as reduce of the mobility and rate of strength development are compensated by using corresponding functional additives. Minimal sufficiency for the rate of hardening accelerator has been confirmed by the dynamics of solution hardening with optimum content for the complex additive obtained and C-3, as well as with different content of calcium formiate.