Flexural behavior of reinforced concrete beams repaired with ultra-high performance fiber reinforced concrete (UHPFRC)

Abstract

Over the past few decades, premature deterioration of reinforced concrete structures exposed to severe environmental actions and mechanical loading has become a serious problem. Previous studies have shown that the use of ultra-high performance fiber reinforced concrete (UHPFRC) improves the structural response and extends the durability of concrete structures. In this study, the flexural behavior of reinforced concrete beams retrofitted with UHPFRC is investigated and experimental results are compared with 3-D finite element analysis.The experiments were performed on reinforced concrete beams repaired in tension and compression zone, with UHPFRC of varying thicknesses. The flexural strength of repaired beams was investigated by four-point bending test and compared with that of reference beam without repair. Experimental and analytical results indicate that the ultimate flexural strength of RC beams repaired with UHPFRC in tension and compression zone is increased, with the increase of UHPFRC thickness. Thereafter, a parametric study was carried out by using MSC/Marc simulation to investigate the influence of tensile properties of UHPFRC and yield strength of tension steel on the flexural capacity of repaired beams. The investigation shows that the UHPFRC improves stiffness and delay the formation of localized cracks, thus, improving the resistance and durability of repaired beams.

Shear strengthening of reinforced concrete beams using prefabricated ultra‐high performance fiber reinforced concrete plates: Experimental and numerical investigation

“…To the authors' best knowledge most of researchers who studied strengthening of RC beams using UHPFRC material numerically assumed perfect bond between RC beam surface and UHPFRC layers or plates which neglect the slippage between concrete and UHPFRC and cannot capture the debonding failure mode. Herein, the cohesive surface model proposed by Sakr was used to model the adhesive surface behavior, in the following section there is a brief discussion explaining the cohesive surface model.…”

“…To the authors´best knowledge most of researchers who studied strengthening of RC beams using UHPFRC material numerically 20,30 assumed perfect bond between RC beam surface and UHPFRC layers or plates which neglect the slippage between concrete and UHPFRC and cannot capture the Poisson's ratio 0.2 0.22…”

“…There are other published studies on strengthening RC structures using casting UHPFRC layers or jackets in situ . Habel et al investigated the flexural performance of composite concrete‐UHPFRC elements.…”

“…There are other published studies on strengthening RC structures using casting UHPFRC layers or jackets in situ. [18][19][20][21][22][23][24][25][26][27] Habel et al 18 investigated the flexural performance of composite concrete-UHPFRC elements. In this study, three configurations for the optimum performance of the composites elements were proposed.…”

Behavior of RC beams strengthened in shear with ultra-high performance fiber reinforced concrete (UHPFRC)

“…Hence, the optimum performance was achieved from the specimens with axis parallel to fiber orientation. Moreover, considerable attention has been paid to strengthen RC structures using UHPFRC layers or jackets, [3][4][5][6][7][8][9][10] presented real applications of UHPFRC for the rehabilitation of crash barrier wall of highway bridge, bridge pier, and industrial floors, and the efficiency of this method for cast in-situ and prefabrication, using standard equipment for concrete manufacturing, was highlighted.…”