Unveiling the flexural strength of corroded prestressed self compacting concrete beams enhanced with M-sand and...

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.