Rehabilitation Systems of Damaged Infrastructures by Using Carbon Fiber Sheets

近年来，通过使用诸如纤维增强塑料（FRP）板的复合包裹物作为外部增强物来修复受损基础设施受到了很多关注。本研究的目的是定量地阐明碳纤维布对受损基础设施的加固效果，并为利用复合材料包裹物建立修复体系提供理论依据。(1)基于线弹性断裂力学理论，建立了复合材料加固梁的力学模型，研究了复合材料加固梁对裂纹强度降低的加固效果、复合材料加固梁的粘结强度和破坏模式。设计了一种三点弯曲试验方法，在混凝土单边缺口梁的受拉区粘贴单向FRP布，以定量评价FRP布的加固效果。(2)将上述试验方法应用于混凝土和水泥 ...更多信息 为了评估加固和修复的修复效果，通过实际现场处理，对带有和不带有中心切口的碳纤维板的ar梁试件进行了粘结。通过检测声发射（AE）活动和AE矩张量分析监测破坏过程以及载荷、应变和裂纹张开位移行为。在此基础上讨论了声发射活动开始时的强化效应与断裂韧性的关系。(3)提出了一种新的剥离试验方法来评估FRP片材与混凝土之间的粘结强度，在该方法中，将薄FRP片材粘结在混凝土块上，并对FRP片材施加面外力以传播剥离。该测试方法给出了表征剥离强度和检查不同表面处理和底漆在能量释放率方面的影响的良好测量。提出了一种简化的基于膜变形的能量释放率测量方法。少

Much attention has been paid in recent years to rehabilitation of damaged infrastructures by using composite wrap such as fiber reinforced plastics (FRP) sheets as external reinforcements. The purpose of this study is to make a quantitative clarification of the reinforcing effects of carbon fiber sheets bonded on damaged infrastructures and to give a theoretical basis to establish a rehabilitation system by using composite wrap.(1) A mechanical model was proposed based on linear elastic fracture mechanics to investigate the reinforcing effect for strength reduction due to a crack, the bonding strength and the failure modes in view of the rehabilitation of cracked beams by using composite wrap. A three-point flexure test method was devised in which a single edge notched concrete beam specimen strengthened externally by bonding unidirectional FRP sheets on the bottom tensile zone to evaluate the reinforcing effects quantitatively.(2) The above test method was applied to concrete and mort … More ar beam specimens with and without a center notch with carbon fiber sheets bonded through the actual spot processing in view of evaluating rehabilitation as reinforcing and repair. The failure process as well as load, strain and crack opening displacement behavior were monitored by detecting acoustic emission (AE) activity and by AE moment tensor analysis. The relation between reinforcing effect and fracture toughness at the initiation of AE activity was discussed based on these results.(3) A new peeling test method to evaluate bonding strength between FRP sheets and concrete was proposed in which a thin FRP sheet was bonded on a concrete block and out-of-plane force was applied to FRP sheet to propagate debonding. This test method gave a good measure to characterize a peeling strength and examine the effects of different surface treatment and primer in terms of energy release rate. A simplified data reduction method was also proposed to measure the energy release rate based on the deformation of membrane. Less