POSSIBILITY OF USING A PRODUCT OF NATURAL POLYMER CHEMICAL PROCESSING TO IMPROVE CONCRETE MIXTURE PLASTICIZING PROPERTIES

Abstract

In modern construction, increasing attention is paid to the search for new materials and technologies that can improve the properties of concrete mixtures. Chemical additives such as superplasticizers and air bubbles are used to improve the workability of the concrete mixture and increase its plasticity. The strength characteristics of concrete mixtures are an important criterion in solving issues related to the profitability of the construction process. The use of plasticizers and hardening accelerators makes it possible to obtain high-strength mixtures with unique characteristics and guarantee high quality construction. Lignosulfonate-based additives have unique properties that can significantly increase the plasticizing characteristics of a concrete mixture. Tests for strength, frost resistance, resistance to aggressive environments, bending and torsion make it possible to evaluate the properties of concrete with lignosulfonate-based additives.While researching, several samples of concrete mixtures with different compositions were prepared. In the experimental testing laboratory, under conditions close to production conditions, a series of experiments was carried out with samples of concrete mixtures for compliance with the requirements of regulatory documents for concrete quality: a lignosulfonate-based additive with concentrations 0.5 %, 1 %, 1.5 % was added to the concrete mixture of compressive strength class B15 to volume 2286 kg/m3.It has been established that the use of a product of natural polymer chemical processing – lignosulfonate – improves the plasticizing properties of concrete mixtures with a two to fivefold increase in mobility and without slowing down the hardening of concrete both in the early (3 days) and late (10–15 days) periods of hardening.It has been revealed that the use of an additive based on lignosulfonate helps to increase the strength of concrete by 25–30 % compared to known plasticizing additives.It has been calculated that the use of a lignosulfonate-based additive helps to reduce cement consumption by 12–15 %.It has been shown that the addition of 1 % lignosulfonate reduces water absorption by 9 % and increases the average strength over 7 days by 10 %, which makes it possible to use the practical results of the research to develop new concrete compositions with improved technical characteristics.