PCCP预应力钢丝涂层防腐电化学试验研究OA

Corrosion-induced fracture of prestressed steel wires is one of the primary failure mechanisms in PCCP,with preventive measures and effectiveness evaluation being key focuses in durability research.To investigate the cor-rosion damage patterns of prestressed steel wires under stress-chloride coupling environments and identify effective anti-corrosion materials meeting durability requirements,this study examined the effects of applied stress on the cor-rosion behavior of bare wires in NaCl solutions at concentrations of 1%,3.5%,10%,and 20%,as well as single-component polyurea-coated wires in 3.5%NaCl solution,through open-circuit potential measurements,corrosion current density analysis,and electrochemical impedance spectroscopy,using stress-free conditions as the control group.For bare wires,chloride concentration predominantly governed corrosion progression,exhibiting the order:3.5%NaCl>1%NaCl>10%NaCl>20%NaCl.Stress only accelerated corrosion in low-concentration solutions.Regarding coated wires,applied stress accelerated coating resistance degradation,yet their corrosion current density remained five orders of magnitude lower than bare counterparts.After 25 days immersion under sustained load,the impedance modulus maintained 2.07×107 Ω·cm²,demonstrating that single-component polyurea coating significantly enhances corrosion resistance of prestressed wires in stress-chloride coupling environments.