The use fibre reinforced polymer (FRP) composites for flexural strengthening of reinforced concrete beams was the first application for these materials, studied in the last decades. Nowadays real applications are found worldwide. Nevertheless, the issues concerning the strengthening of continuous RC beams are currently an interesting research field, since the largest part of the past studies was done on simply supported beams. This paper presents the results of experimental tests on continuous reinforced concrete (RC) beams tested on real scale dimensions. The internal flexural steel reinforcement was properly designed in order to allow steel yielding before the collapse; the shear reinforcement was designed in order to prevent shear failures by using steel stirrups. Tests included un-strengthened control beams; the other specimens were strengthened with different strengthening schemes using externally epoxy-bonded carbon fiber reinforced polymer (CFRP) sheets. Discontinuous transverse wrapping was provided in order to prevent premature debonding of the FRP flexural sheets on tension sides. The key-issue of a possible loss in ductility due to the presence of FRP, that may take to failure before a sufficient amount of moment redistribution was monitored. The experimental results show that it is possible to achieve a sufficient grade of redistribution if the strengthening configuration is properly chosen, confirming the expected results provided by two simple numerical models.
Effects of CFRP strengthening on the moment redistribution of reinforced concrete continuous beams
AIELLO, Maria Antonietta;MICELLI, Francesco;VALENTE, LUCA
2009-01-01
Abstract
The use fibre reinforced polymer (FRP) composites for flexural strengthening of reinforced concrete beams was the first application for these materials, studied in the last decades. Nowadays real applications are found worldwide. Nevertheless, the issues concerning the strengthening of continuous RC beams are currently an interesting research field, since the largest part of the past studies was done on simply supported beams. This paper presents the results of experimental tests on continuous reinforced concrete (RC) beams tested on real scale dimensions. The internal flexural steel reinforcement was properly designed in order to allow steel yielding before the collapse; the shear reinforcement was designed in order to prevent shear failures by using steel stirrups. Tests included un-strengthened control beams; the other specimens were strengthened with different strengthening schemes using externally epoxy-bonded carbon fiber reinforced polymer (CFRP) sheets. Discontinuous transverse wrapping was provided in order to prevent premature debonding of the FRP flexural sheets on tension sides. The key-issue of a possible loss in ductility due to the presence of FRP, that may take to failure before a sufficient amount of moment redistribution was monitored. The experimental results show that it is possible to achieve a sufficient grade of redistribution if the strengthening configuration is properly chosen, confirming the expected results provided by two simple numerical models.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
