FEATURES OF DEFORMATION, DESTRUCTION AND CALCULATION OF DAMAGED BASALT CONCRETE BEAMS REINFORCED WITH CARBON FIBER CLOTH

Abstract

The  article  presents  the  results  of  tests  of  concrete  beams  with  basalt—plastic 
reinforcement (BFRP). These beams in previous studies were brought to the limit (ULS) state, and 
then reinforced with carbon fiber webs (CFRP). 
The established character of deformation, crack development and fracture used in beams with 
large (a/d=3) and medium (a/d=2) shear spans corresponded to the stress — strain state of almost 
balanced normal cross section. It was characterized by the achievement in the outer carbon—plastic 
layer of the strengthening of ultimate deformations and tensile stresses, and in the compressed zone 
of concrete — closed (in the descending section of the diagram " σ с —ε с  ") stresses and strains. 
The destruction of beams with small (a/d=1) landslides was accompanied by further opening of 
previously formed inclined cracks and rupture of closed carbon fiber shirts on the side faces. 
Reinforcement of normal sections is recommended to be designed for cases of achievement of 
characteristic  stresses  in  the  stretched  rod  reinforcement  with  the  subsequent  rupture  of  external 
FAP—FRP reinforcement without destruction of the compressed zone of concrete. 
The resulting transverse force in the inclined section of the beam consists of the transverse 
forces perceived by the concrete of the compressed zone above the top of the dangerous inclined 
crack, composite reinforcement crossed by the crack, clamps or canvas with FAP—FRP. 
The method of determining the load—bearing capacity of inclined sections of unreinforced 
concrete  beams  reinforced  with  NCA—FRP  is  described  in  previously  published  works  of  the 
authors. 
The bearing capacity of the ULS—supported support sections of beam structures reinforced 
with FAP—FRP materials should be determined, first of all, by the action of the bending moment on 
the critical inclined crack.