Bhagwat Yamuna, Nayak Gopinatha
Department of Civil Engineering, Manipal Institute of Technology, Manipal Academy of Higher Education, Manipal, Karnataka, 576104, India.
Sci Rep. 2025 May 12;15(1):16436. doi: 10.1038/s41598-025-01264-z.
Prestressing steel corrosion is one of the barriers to the serviceability of prestressed concrete structures. The presence of aggressive environmental conditions leads to a reduction in the efficiency of the structures by degradation. Hence, untimely deterioration of the structures before completion of the expected service life is of great concern for engineers and researchers. The development of corrosion is faster and more severe in prestressed steel than in normal steel because of the high stress in prestressing steel. Therefore, a detailed investigation of the prestressed concrete structure under a corrosive environment is essential. This particular study focused on studying the corrosion effect on flexural behaviour of prestressed self compacting concrete beams made of M40 and M60 grade mixes using M-sand as fine aggregate, also with and without polypropylene fibre. The beam specimens were artificially corroded by the accelerated corrosion method, and the flexural strength of the corroded and non corroded prestressed concrete beam specimens were studied under four point bending method. The comparison study of prestressed concrete beams with and without polypropylene fibre showed that corrosion levels obtained in the corroded prestressed concrete beam specimens with fibre were less than the corroded prestressed concrete beam specimens without fibre at a constant period with a constant current. The corrosion levels obtained in M60 self compacting concrete were less than that of M40 self compacting concrete specimens. Also, corrosion of the strand reduced the cracking load, ultimate load, ultimate deflection, energy absorption capacity and stiffness of prestressed concrete beam specimens. The study concludes that the addition of polypropylene fibre to the self compacting concrete mixes improves the corrosion resistance of prestressed concrete beam and the flexural performance of the corroded prestressed concrete beam.
预应力钢筋腐蚀是预应力混凝土结构适用性的障碍之一。侵蚀性环境条件的存在会导致结构因劣化而效率降低。因此，在预期使用寿命结束前结构的过早劣化是工程师和研究人员极为关注的问题。由于预应力钢筋中的高应力，其腐蚀发展比普通钢筋更快、更严重。因此，对腐蚀环境下的预应力混凝土结构进行详细研究至关重要。本专项研究聚焦于使用机制砂作为细集料、采用M40和M60级配合比制成的、含和不含聚丙烯纤维的预应力自密实混凝土梁的弯曲性能的腐蚀影响研究。梁试件采用加速腐蚀法进行人工腐蚀，并采用四点弯曲法研究腐蚀和未腐蚀的预应力混凝土梁试件的抗弯强度。对含和不含聚丙烯纤维的预应力混凝土梁的对比研究表明，在恒定电流下的恒定时间段内，含纤维的腐蚀预应力混凝土梁试件的腐蚀程度低于不含纤维的腐蚀预应力混凝土梁试件。M60自密实混凝土的腐蚀程度低于M40自密实混凝土试件。此外，钢绞线的腐蚀降低了预应力混凝土梁试件的开裂荷载、极限荷载、极限挠度、能量吸收能力和刚度。研究得出结论，在自密实混凝土配合比中添加聚丙烯纤维可提高预应力混凝土梁的耐腐蚀性以及腐蚀后预应力混凝土梁的抗弯性能。
