Behavior of Auxetic Steel Wire RC Columns Exposed to Elevated Temperature

TWENTY-FOUR RECTANGULAR RC COLUMN SPECIMENS, CONSTRUCTED AT 1/3 SCALE, WERE TESTED UNDER AXIAL LOADING TO INVESTIGATE THE USE OF ASWM (ONE, TWO, THREE, FOUR, AND FIVE LAYERS) EXPOSED TO ELEVATED TEMPERATURES. SIX OF THE COLUMN SPECIMENS WERE SUBJECTED TO LABORATORY TEMPERATURE (CONTROL OR UN-DAMAGED SPECIMENS) OF 23OC. EIGHTEEN OF THE COLUMN SPECIMENS WERE SUBJECTED TO ELEVATED TEMPERATURES (SIX COLUMNS AT 250OC, SIX COLUMNS AT 500OC, AND SIX COLUMNS AT 750OC) FOR 2 HR. THE OBTAINED RESULTS CLEARLY SHOWED THAT EACH AXIAL LOAD RESISTANCE, TOUGHNESS, AND STIFFNESS WERE ALL NEGATIVELY AFFECTED BY ESCALATED TEMPERATURE DEGREES. ALSO, THE CONFINEMENT EFFECTIVENESS IN TERMS OF THE ULTIMATE LOAD WAS DECREASED WITH THE INCREASE IN CONCRETE COMPRESSIVE STRENGTH (UN-DAMAGED). THE NUMBER OF ASWM LAYERS SIGNIFICANTLY INFLUENCED THE DUCTILITY, ENERGY ABSORPTION, AND ULTIMATE LOAD IMPROVEMENT PERCENTAGE. THE NUMBER OF THE ASWM LAYERS CONSIDERABLY ENHANCED THE DUCTILITY UP TO A CERTAIN NUMBER OF ERECTED LAYERS; HOWEVER, ADDING MORE LAYERS HAD NO APPARENT EFFECT.