Controlling changes caused by holes by adding fibers to composite concrete components

Abstract

AbstractCrack propagation can be affected by the holes of the placement of rebars in the reinforced concrete and the resulting changes in the homogeneous structure of concrete. This experimental study aimed at investigating the fiber self-compacting concrete failure and crack propagation in concrete specimens with circular central holes and contain 2, 4, and 8 fiber percentages. The crack propagation mechanisms under the uniaxial compressive strength of the concrete were studied by investigating the holes created by rebars buried in the reinforced concrete. Three concrete mix designs with different compressive strengths of 27, 30, and 33 MPa were used for detailed analysis of the fiber concrete behavior by 224 standard 150 mm cubic specimens. The results showed the insignificant impact of small holes with an approximate area of 1.4% of the specimen surface area on the failure structure so that crack propagation in this case was similar to that occurred in the hole-free concrete. The compressive strength of concrete decreased, by increasing the crack prorogation around the holes. The compressive strength of the concrete may be reduced significantly by increasing the hole diameter. Taking into account these factors in the design of the connection core can reduce the compressive strength of concrete by 30% depending on the rebar grid.