Based on the Canadian Standards Association (CSA) criteria,105 pullout specimens were tested to investigate the effect of different rib geometries on bond strength of glass fiber reinforced polymer (GFRP) rebars embed...Based on the Canadian Standards Association (CSA) criteria,105 pullout specimens were tested to investigate the effect of different rib geometries on bond strength of glass fiber reinforced polymer (GFRP) rebars embedded in concrete. Two kinds of conventional reinforcing rebars were also studied for comparison. Each rebar was embedded in a 150 mm concrete cube,with the embedded length being four times the rebar diameter. The experimental parameters were the rebar type,rebar component,rebar diameter,rebar surface texture,rib height,rib spacing and rib width. Theoretical analysis was also carried out to explain the experimental phenomena and results. The experimental and theoretical results indicated that the bond strength of GFRP rebars was about 13%～35% lower than that of steel rebars. The bond strength and bond-slip behavior of the specially machined rebars varied with the rebar type,rebar diameter,rebar surface texture,rib height,rib spacing and rib width. Using the results,design recom-mendations were made concerning optimum rib geometries of GFRP ribbed rebars with superior bond-slip characteristics,which concluded that the optimal rib spacing of ribbed rebars is the same as the rebar diameter,and that the optimal rib height is 6% of the rebar diameter.展开更多
Based on the Canadian Standards Association(CSA) criterion,experiments on 30 pull-out specimens were conducted to study the bond strength of deformed GFRP rebars with 8 different surface configurations.Each rebar was ...Based on the Canadian Standards Association(CSA) criterion,experiments on 30 pull-out specimens were conducted to study the bond strength of deformed GFRP rebars with 8 different surface configurations.Each rebar was embedded in a 150 mm concrete cube,and the test embedded length was four times of the rebar diameter.Relationship between the mode of failure,the average bond strength and the average bond strength-slip for each rebar was analyzed.Results show that the failure mode of all specimens is the shearing off or desquamation of ribs,no splitting cracks appear on the cube specimens.The bond stress of deformed GFRP rebars mainly depends on the mechanical interaction between the ribs of the bar and the surrounding concrete,and the bond strength of deformed GFRP rebars is improved obviously.The optimal rib spacing is less than 2.5 times of the rebar diameter,and the rib height is more than 3% of the rebar diameter.展开更多
基金Project (No. 200431882021) supported by the Western Communi-cation Construction and Science & Technological Project,China
文摘Based on the Canadian Standards Association (CSA) criteria,105 pullout specimens were tested to investigate the effect of different rib geometries on bond strength of glass fiber reinforced polymer (GFRP) rebars embedded in concrete. Two kinds of conventional reinforcing rebars were also studied for comparison. Each rebar was embedded in a 150 mm concrete cube,with the embedded length being four times the rebar diameter. The experimental parameters were the rebar type,rebar component,rebar diameter,rebar surface texture,rib height,rib spacing and rib width. Theoretical analysis was also carried out to explain the experimental phenomena and results. The experimental and theoretical results indicated that the bond strength of GFRP rebars was about 13%～35% lower than that of steel rebars. The bond strength and bond-slip behavior of the specially machined rebars varied with the rebar type,rebar diameter,rebar surface texture,rib height,rib spacing and rib width. Using the results,design recom-mendations were made concerning optimum rib geometries of GFRP ribbed rebars with superior bond-slip characteristics,which concluded that the optimal rib spacing of ribbed rebars is the same as the rebar diameter,and that the optimal rib height is 6% of the rebar diameter.
基金Sponsored by the Western Communication Construction and Science & Technological Project(Grant No.200431882021)the National Science Fundfor Distinguished Young Scholars (Grant No.50525823)
文摘Based on the Canadian Standards Association(CSA) criterion,experiments on 30 pull-out specimens were conducted to study the bond strength of deformed GFRP rebars with 8 different surface configurations.Each rebar was embedded in a 150 mm concrete cube,and the test embedded length was four times of the rebar diameter.Relationship between the mode of failure,the average bond strength and the average bond strength-slip for each rebar was analyzed.Results show that the failure mode of all specimens is the shearing off or desquamation of ribs,no splitting cracks appear on the cube specimens.The bond stress of deformed GFRP rebars mainly depends on the mechanical interaction between the ribs of the bar and the surrounding concrete,and the bond strength of deformed GFRP rebars is improved obviously.The optimal rib spacing is less than 2.5 times of the rebar diameter,and the rib height is more than 3% of the rebar diameter.
