RESEARCH OF THE INFLUENCE OF THE CONTENT OF SAND AND MODIFIING ADDITIVES ON THE PROPERTIES OF POLYMER CONCRETE COMPOSITIONS

Abstract

Purpose. Establishment of the influence of the content of sand and modifying additives on the hardness, compressive strength, and impact strength of polymer concrete compositions. Methodology. Polymer concrete compositions in the form of round pancakes, sticks and bars based on polyester resin of the CHROMOPLAST GP 2000 brand, hardener (organic peroxide for cold curing) of the Luperox K1 brand, cobalt stearate (cobalt salt of stearic acid), styrene and river sand were subject of investigation. Samples of polymer concrete composites were obtained in two stages: 1) mixing the resin with sand 2) the addition of hardener, styrene and cobalt stearate. To obtain a hardened polyester composition, metal forms with bent sides were used; ceramic boats (not enameled) metal molds 2 cm high. Preparation of the composition was carried out in the following sequence: first, resin was mixed with sand, then hardener, cobalt stearate and styrene were added. The following sequence of preparation of the composition also took place: first the resin and hardener were mixed, only then sand mixed with styrene and cobalt stearate was added. The forms were loaded into a heating cabinet and heated to a temperature of 100 °C for 30-40 minutes. After cooling in the form of the product was removed. The hardness, compressive strength and toughness of the developed compositions were investigated by standard methods. Results. It was found that an increase in sand content from 0 to 90% of the mass. in polymer concrete compositions leads to an increase in hardness by ~ 466%, as well as a decrease in compressive strength by ~ 62% and impact strength by ~ 50%. Scientific novelty. An increase in the hardness index and a decrease in the compressive strength and toughness of polymer concrete compositions with an increase in the sand content to 90 % of the mass was established. This is because the sand has a higher hardness than the polyester resin, and accordingly, an increase in its content leads to an increase in the hardness of the composition. The decrease in compressive strength and toughness is due to a decrease in the amount of binder, due to which the composition becomes more fragile. Practical value. The developed polymer concrete compositions can be used in construction, as well as for repairing damaged concrete surfaces and eliminating cracks.