Effect of recycled aggregate on behavior of tied and spiral reinforced fibrous circular short columns

This study focuses on studying the behavior of fibrous circular short columns (tiedand spirally reinforced) using recycled coarse aggregate (f'c, ft, Ec, and fr) by usingrecycled aggregates with comparison to normal aggregates with and without usingsteel fibers. For this purpose, ten (10) short columns were cast at five groups eachof two circular columns(tied and spiral of 150 mm radius x 600mm height) withdifferent percentages of recycled coarse aggregate (0% , 50% , and 100% ) anddifferent percentages of steel fiber (0% , 0.5% and 1% ). The study showed thatwhen adding the 50% normal aggregates with 50% recycled aggregates, decreasesof (10% , 18% , 30% and 22% ) for (compressive strength, splitting tensile strength, flexural strength and elasticity module), respectively were observed, and whenreplacing the 100% normal aggregates with 100% recycled aggregates, decreasesof (30% , 35% , 58% and 63% ) for (Compressive strength f'c, splitting tensilestrength ft, flexural strength fr and elasticity module Ec), respectively wereobserved. The changes on the compressive strength of adding steel fibers to theRAC by a proportion of (0.5% and 1 % ) resulted in a significant increase of about(14 % and 35 % ), This study focuses on studying the behavior of fibrous circular short columns (tiedand spirally reinforced) using recycled coarse aggregate (f'c, ft, Ec, and fr) by usingrecycled aggregates with comparison to normal aggregates with and without usingsteel fibers. For this purpose, ten (10) short columns were cast at five groups eachof two circular columns(tied and spiral of 150 mm radius x 600mm height) withdifferent percentages of recycled coarse aggregate (0% , 50% , and 100% ) anddifferent percentages of steel fiber (0% , 0.5% and 1% ). The study showed thatwhen adding the 50% normal aggregates with 50% recycled aggregates, decreasesof (10% , 18% , 30% and 22% ) for (compressive strength, splitting tensile strength, flexural strength and elasticity module), respectively were observed, and whenreplacing the 100% normal aggregates with 100% recycled aggregates, decreasesof (30% , 35% , 58% and 63% ) for (Compressive strength f'c, splitting tensilestrength ft, flexural strength fr and elasticity module Ec), respectively wereobserved. The changes on the compressive strength of adding steel fibers to theRAC by a proportion of (0.5% and 1 % ) resulted in a significant increase of about(14 % and 35 % ), respectively.