FRACTURE TOUGHNESS OF NANOFIBER-REINFORCED CONCRETE ON NORMAL SEPARATION AND IN-PLANE SHEAR

Tests were carried out on various nanoconcrete matrices and with diff erent dispersed reinforcement fabric: carbon nanotubes, basalt fi ber (polymer, 3 types of steel, and their combinations). It has been established that the value of the stress intensity factor KIIC in the case of normal separation increases most with steel fi ber (up to 400%). Polymer fi ber exerted the least eff ect on crack resistance  up to 40%. The infl uence of dispersed reinforcement on the stress intensity factor in the case of normal separation depends on the type of concrete matrix, on the material of fi ber fabric, and on the quantity of the latter. As a result of the tests, the values of KIIC have been obtained for various dispersed-reinforced nanoconcretes, diff ering in the compressive strengths of the nanoconcrete matrix and in polyreinforcement with dispersed fabric at diff erent structural levels. It has been established that dispersed reinforcement has a signifi cant eff ect on increasing the crack resistance of the material. Increasing the value of KIIC relative to nonreinforced nanoconcrete was from 74 to 150% with steel wire fi ber, from 29 to 129% with steel fi ber from sheet, from 14 to 131% with polymer fi ber, and from 22 to 124% with polyreinforced material.
   
Author:  E. A. Sadovskaya ,  E. N. Polonina ,  S. N. Leonovich ,  S. A. Zhdanok ,  V. V. Potapov
Keywords:  fi brous concrete, fi brous nanoconcrete, fi ber, crack resistance, fracture toughness, normal separation, critical stress intensity factor
Page:  945