ВПЛИВ ПОЛІМЕРНИХ ДОБАВОК НА МІЦНІСТЬ ТА ЕЛЕКТРИЧНИЙ ОПІР БЕТОНУ

Abstract

In this article the increase possibility of concrete electrical resistance owing to the material addition with electrical insulating
properties such as bitumen emulsion and acrylic primer is investigated. Such concrete can be used for prestressed concrete sleeper production. It will improve the insulation resistance of the signal track circuits and raise the reliability of the transit processes. Moreover, the manufacture of the various constructions from such concrete (foundations, piles, supporting blocks,
bridge and tunnel structures, etc.) decreases the effect of the leakage currents and ground currents on the electrical corrosion development in the railway transport constructions and increases their durability. In rain period the wall material becomes wet, their electrical resistance rises sharply. The possible way of this problem solution can be the usage of concrete with
the improved electrical insulation properties. Experimental results have established that the bitumen emulsion addition has increased the electrical resistance 3.5 times compared with the concrete without the additives. The replacement water for making concrete with acrylic primer doubles the electrical resistance. While the strength has declined slightly under conditions of the air-hardening of concrete. This slow hardening is analogous to the plasticizers or hydrophobic additives action. The water-soluble bitumen emulsion is the effective hydrophobic additive which increases the wetting angle of the concrete capillary walls 2 times. The electrical resistance growth of the concrete with bitumen emulsion happens both due to the decline of the capillary height in the hydrophobic capillaries and because of the pore block by the bitumen particles. Under this condition the free water movement from the concrete constructions exterior into concrete is inhibited, whereas its durability increases.