CAJ | 학술논문

基于混凝土碳化理论分析预应力筋腐蚀开始时间，提出预应力钢绞线腐蚀截面积退化时变模型。通过已有试验成果对比研究，提出由腐蚀电流密度和时间表达的腐蚀钢绞线力学性能退化时变模型，包括名义极限强度、极限延伸率、名义弹性模量时变模型；并推导建立由于钢绞线腐蚀引起的预应力损失时变模型。在此基础上，以预应力混凝土空心板桥为例，分析预应力钢绞线腐蚀后其梁体应力、抗弯承载力和可靠度等的经时变化。研究表明：预应力筋是预应力混凝土梁桥性能表现的重要参数，一旦发生腐蚀，其应力水平、抗弯承载力及可靠度将急剧下降，在短短几年内就可能危及桥梁的安全。
기우혼응토탄화이론분석예응력근부식개시시간，제출예응력강교선부식절면적퇴화시변모형。통과이유시험성과대비연구，제출유부식전류밀도화시간표체적부식강교선역학성능퇴화시변모형，포괄명의겁한강도、겁한연신솔、명의탄성모량시변모형；병추도건립유우강교선부식인기적예응력손실시변모형。재차기출상，이예응력혼응토공심판교위례，분석예응력강교선부식후기량체응력、항만승재력화가고도등적경시변화。연구표명：예응력근시예응력혼응토량교성능표현적중요삼수，일단발생부식，기응력수평、항만승재력급가고도장급극하강，재단단궤년내취가능위급교량적안전。
This paper analyzes start time of corrosion of prestressed reinforcements based on the theory of concrete carbonization and proposes a time -varying model of cross -sectional area degradation of prestressed steel strand corrosion .By comparative research on existing test results , the paper proposes a time-varying model of mechanical property degradation of corroded steel strand expressed by corrosion current density and time , including nominal ultimate strength , maximum elongation and time -varying model of nominal elastic modulus; and derives and establishes time -varying model of prestressed loss caused by steel strand corrosion .On this basis the paper analyzes ongoing changes of beam stress , bending capacity and reliability , etc.after prestressed steel strand corrosion .The research shows that prestressed reinforcement is an important parameter for performance of prestressed concrete beam bridges , and its stress level , bending capacity and reliability will decrease sharply and may endanger the safety of bridges in a few years once corrosion happens .