Flwxural behavior of fiber concrete with conventional steel reinforcement

Fiber concrete were located at different parts in reinforced concrete beamsections and the flexural behavior of these beams were studied. Layers of fiberconcrete were located in the tensile zone, the compressive zone and the whole beamsection. The thickness of fib er concrete layers were varied between 2.5 cm to 10 cmwhere the beam dimensions were 10x20x130 cm representing 0.125 to 0.5 of beamdepth.Fiber concrete containing l.5% steel fibers volume fraction and fiber aspectratio of 100 were found to give maximum strength and were used in this study. Themain reinforcement of the beam specimens were varied from 2~10. 2~13 to 2~16.It was found that the addition of steel fiber to R. C beams increases the firstcrack load, the ultimate load and decreases crack width and beam deflection.R. C beams containing reinforcement 2~ 13 showed an increases in first crackload with the increase in fiber concrete layer thickness up to 150% of that for thecontrol beams.The presence of steel fibers in the compression zone increases the crushingstrength and prevent sudden failure when the beam is subjected to the ultimate load.The experimental data indicates that this procedure can be used to repair R.Cdamaged beams, where 40% of the main reinforcement area is lost by corrosion, andas a result of this repair an increase of the load bearing capacity to the level of theR. C control beams occurs.The first crack load was found to increase when fiber concrete layer was usedas a repair material with thickness layer of 5.0 cm by double when compared with itsvalue for control beam.-ii-