SEISMIC BEHAVIOR OF EXTERIOR RC BEAM-COLUMN JOINTS RETROFITTED USING CFRP SHEETS

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DOI:

https://doi.org/10.1590/1679-78255910

Abstract

BEAM COLUMN JOINTS EXPERIENCE HUGE SHEAR FORCES DURING SEISMIC EVENTS, AND THIS MAY LEAD TO BRITTLE FAILURE. RESEARCHERS HAVE RECOMMENDED DIFFERENT RETROFITTING TECHNOLOGIES AND TECHNIQUES TO STRENGTHEN BEAM-COLUMN JOINTS.  PREVIOUS RESEARCHES HAVE DEMONSTRATED THE EFFECTIVENESS OF FIBRE REINFORCED POLYMER COMPOSITE TO IMPROVE THE SHEAR, FLEXURAL AND AXIAL CAPACITIES OF BEAMS, COLUMNS AND JOINT STRUCTURES. IN THIS STUDY, TWO FULL SCALES IDENTICAL WITHOUT ANY TRANSVERSE REINFORCEMENT IN THE JOINTS AREA WERE PREPARED, WHERE ONE JOINT IS THE CONTROL SPECIMEN (CS) WHILE THE OTHER JOINT WAS ENHANCED USING CARBON FIBRE REINFORCED POLYMER FABRICS (CFRP); THE COLUMN AND BEAM AT AND NEAR THE JOINT AREA WERE MODIFIED TO PRODUCE ROUNDED EDGES, WHICH CHANGE THE SHAPE OF THE SECTION FROM SQUARE TO SQUIRCLE. THE LOADING IS APPLIED BY MEANS OF TWO HYDRAULIC ACTUATORS THAT ALLOW THE APPLICATION OF AXIAL AND REVERSED QUASI-STATIC CYCLIC LOADING. THE STRENGTHENED JOINT HAS A GREATER LOAD-BEARING CAPACITY AND HIGHER DUCTILITY COMPARED WITH THE CONTROL SPECIMEN. MODIFYING THE BEAM AND COLUMN TO OBTAIN SQUIRCLE SECTIONS HAVE THE EFFECT OF DIMINISHING THE POSSIBILITY OF CFRP DEBONDING AND ENHANCING THE CONFINING EFFECT OF CFRP.  THE RC EXTERIOR JOINTS WERE MODELLED UTILIZING A FINITE ELEMENT PROGRAMMING KNOWN AS ANSYS. THE EXPERIMENTAL RESULT IS STRONGLY CORRELATED WITH THAT OF THE FINITE ELEMENT. ALL PREVIOUS DETAILS ARE PRESENTED IN THIS PAPER.

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Published

2020-03-27

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