SELF-COMPACTING CONDUCTIVE CONCRETE OF NORMAL HARDENING BASED ON PORTLAND CEMENT WITH TECHNICAL CARBON AND CARBON FIBER

An approach to obtaining self-sealing conductive concrete of normal hardening is presented. The results of a study of the properties of self-sealing concrete of normal hardening based on Portland cement obtained by the joint introduction of carbon black of two grades TU P-803 and TU K-354 with their mass ratio of 4:1 and volume concentration in a mixture equal to 0.25%, as well as carbon fiber with a length of 3mm in an amount of 1% by weight of cement are presented. Con-crete was obtained with a specific electrical resistance equal to 0.25 Ohms * m, which does not increase during the harden-ing process, a strength of 53 MPa at the age of 28 days, frost resistance F200, water resistance W20, tensile strength at bending 8.2 MPa. Resistive heating elements with a capacity of 600 W/m2 or more have been obtained, providing the possi-bility of obtaining coatings with an anti-icing effect. It is shown that drying concrete of the developed composition can in-crease the conductivity by 50%, which is associated with an improvement in the contact between conductive particles caused by their compression during shrinkage, the value of which decreases with an increase in the amount of carbon fiber from 0.25% to 1% by weight of cement. It is noted that with an increase in the applied voltage to the sample, its electrical resis-tivity decreases, the more the carbon fiber content is in the range of 0.25-1% of the cement weight.