EXPERIMENTAL EVALUATION OF HIGH-PERFORMANCE FIBER REINFORCED CEMENT COMPOSITES BEHAVIOR

High-performance ber cementitious composites are newmaterials in construction industry. Investigation intotheir behavioral characteristics needs experiments dueto the lack of data. In this study, tensile, compressiveand bending behavior of this material is examined us-ing experimental tests"High-performance ber rein-forced cementitious composites (HPFRCC) have strainhardening response under straight tension after cracking.Numerous cracks are formed before the crack widen-ing occurrence when these composites show hardeningbehavior. HPFRCC are basically integrated with twomain components including ber and mortar. Thesetwo ingredients are interactively a ected due to inter-facial bonding which develop a strong composite. Theadvantages of HPFRCC in comparison with normal and ber reinforced concrete (FRC) are ductility, durabil-ity, and high-energy absorption capacity. In this paper,evaluation of strain hardening behavior in HPFRCC isconducted using straight tension and tensile strain-stresscurve. Moreover, bending behavior, load-displacementcurve, and toughness factor of this material are evalu-ated using four-point bending test, and the performanceis compared with bending behavior of normal concrete.In these tests, three ber types, including hooped steel ber, corrugated steel ber, and poly propylene ber, areused in the mortar separately and in combination witheach other by volume percentage of 1.5%. To achievea proper strain hardening behavior, di erent mix ra-tios are investigated and the best mix design is deter-mined. The results showed that all specimens mixedwith bers have strain hardening behavior accompanied by more cracks; consequently, the strength and strainof the HPFRCC specimens are increased signi cantlycompared to those of normal concrete. The strengthof HPFRCC specimens is between 5 to 8 times greaterthan that of normal concrete. In addition, the ultimatestrains of the specimens are 70 to 100 times higher thanthat of normal concrete. Furthermore, toughness fac-tor of HPFRCC specimens is 5 to 9 times higher thanthat of normal concrete. It is revealed that the mechan-ical properties of HPFRCCs have been considerably en-hanced compared to normal concretes. HPFRCCs canbe applied as an appropriate technique to restrain the re-inforcement congestion, decrease the high value of trans-verse reinforcements at beam-column joints, and alsoimprove the shear capacity and ductility of the mem-bers.