HEAT-RESISTANT CORUNDUM CONCRETE
REINFORCED WITH ALUMINUM OXIDE FIBERS SYNTHESIZED
WITHIN A MATRIX DURING FIRING.
PART 2. THEORETICAL PREREQUISITES FOR IMPROVING REFRACTORY
CONCRETE HEAT RESISTANCE REINFORCED WITH FINE FIBERS
V. N. Sokov
and V. V. Sokov
Translated from Novye Ogneupory, No. 6, pp. 25 – 28, June, 2014.
Original article submitted March 12, 2014.
Different deformation stages of concrete reinforced with fibers are considered. It is apparent that under certain
conditions of their location within matrices it is possible to improve component mechanical properties consid
erably and delay crack formation. Strong adhesion between fibers and matrix is necessary in order that a com-
posite behaves as a structurally integral material.
Keywords: deformation, dispersion reinforcement, matrix, concrete, stress, cracks, mixture rule, composite,
increasing failure, heat resistance.
In publication  it is emphasized that the relative vol-
ume content of fibers within a composite should be quite
high in order that the proportion of load perceived by a fiber
is at a maximum. However, if the fiber content with material
exceeds a certain level, then this may lead to worsening of
materials properties as a result of the fact that the matrix will
not be in a condition to wet and impregnate fiber bundles. As
a result if this fiber adhesion to a matrix decreases and cavi
ties may form within a composite.
Four deformation stages are considered in  in develop
ing structural materials reinforced with fibers: 1) elastic de
formation of fiber and matrix; 2) elastic deformation of fiber
and plastic deformation of matrix; 3) plastic deformation of
fiber and matrix; 4) composite failure.
The elasticity modulus of a composite E
in stage 1 is de
termined proceeding from a “mixture rule”, i.e., it is assumed
that the modulus of a composite is distributed between fibers
are fiber and matrix elasticity moduli respec-
are fiber and matrix volume fractions respec-
In stage 2 the matrix deformation curve is not linear, and
the elasticity modulus of a composite is calculated at each
point of a curve by an equation
is slope of the matrix deformation curve with
Analytical dependences derived taking account of these
observations in order to determine composite strength s
elasticity modulus E
relate to a case when a composite in
volves quite a ductile matrix, capable of receiving together
with reinforcing fibers a considerable stress without crack
formation. Normally with reinforcement of a matrix with
brittle fibers stage 3 in operation of composite material does
not happen. With ductile fibers E
in stage 3 composite
modulus is also expressed the same as in stage 2. These oper
ating principles, taking account of appropriate corrections,
may also be extended to composites with a matrix based on
concrete materials. It should be assumed that with dispersed
concrete reinforcement of a comparatively brittle matrix of
high-strength and high-modulus fibers, having higher values
Refractories and Industrial Ceramics Vol. 55, No. 3, September, 2014
1083-4877/14/05503-0227 © 2014 Springer Science+Business Media New York
Part 1 of the article published in Novye Ogneupory No. 5 (2014).
FGBOU VPO Moscow State Building University, Moscow, Russia.