FRP锚钉锚固长度对FRP加固混凝土构件拉拔性能影响的试验研究

FRP锚钉是能有效阻止FRP加固混凝土构件界面剥离的前沿方法.为了测定FRP锚钉的不同锚固长度对FRP加固混凝土构件粘结性能的影响,采用拉拔试验,参照ACI规范的试验方法,测定了不同锚固长度下FRP加固混凝土构件的拉拔荷载.试验用不安装锚钉的控制试件和安装了15 mm、30 mm、45 mm三组FRP锚钉的试验试件,结果发现,锚固长度不同,FRP加固混凝土构件的破坏模式也各不相同,主要表现为混凝土内部浅层剥离、混凝土锥形破坏、混凝土锥形破坏联合锚钉部分拉拔破坏、混凝土浅层剥离联合锚钉断裂破坏以及FRP加固层内部浅层剥离联合部分混凝土浅层剥离破坏;FRP锚钉的锚固长度越长,加固试件的粘结性能越好;混凝土圆柱体抗压强度设计为30 MPa时,FRP锚钉的锚固长度应不得小于30 mm.试验结论可以为FRP锚钉的设计制作提供参考.

Experimental Investigation on the Pullout Properties of Concrete Structures Strengthened by FRP Influenced by Anchorage Depth

FRP anchors are proposed to be advanced in impeding debonding failure between strengthened concrete surface and FRP.Influence of varied depth of FRP anchors on pullout properties of FRP strengthening concrete structures is comparatively investigated by pullout experiment that is in light of ACI experimental guidance.The parameters are set by control specimen and experimental specimens which are armed with 3 groups of anchors whose depth are 15 mm,30 mm and 45 mm,respectively.To analyze the results,the failure modes of debonding inside of shallow concrete,concrete cone,concrete cone combined with partial anchors pullout,debonding inside of shallow concrete combined with anchor rupture and debonding in both shallow concrete and FRP are totally derived.Moreover,the bond strength of FRP and concrete surface are increased with depth of FRP anchors.As well,the depth of the anchors are supposed to set more than 30 mm when applied to concrete with cylindrical compressive strength of 30 MPa.To sum,conclusions for this experiment is available to aid design of FRP anchors.