STUDY OF MECHANICAL PROPERTIES OF RC BEAMS AFTER REINFORCING THE OPENING ON THE BENDING SHEAR SECTION

Considering the different size of opening， the mechanical properties of the RC beams with opening on the shear bending section， as well as the beams with opening filled with CGM and reinforced by CFRP were researched． The results showed that the growth of deflection of the beam with an opening was increased and its cracks were widened， at the same time its bearing capacity was decreased considerably． The opening made the failure mode of beam become the shear failure，which influenced the safety of beam seriously． The bigger the opening， the more seriously the damage． When the opening in a certain range( d00. 4h) ， the bearing capacity of the beams filled with CGM and reinforced by CFRP was improved effectively，and the growth of deflection at midspan of the beams was slowed down． After filling with CGM and reinforcing by CFRP， the bottom reinforcement of beams could yield， and the failure mode became the bending failure，and whose mechanical properties could be restored to the state of uncracked beams． But with the increase of opening size， the cracks of the beam reinforced with CFRP were widened． The result would provide references for the reinforcement of the RC beams with openings at the shear bending section．