Issue 35

W. Xu et alii, Frattura ed Integrità Strutturale, 35 (2016) 481-491; DOI: 10.3221/IGF-ESIS.35.54 488 Figure 8: Curves of load-displacement (axial compression ratio 0.2). Figure 9: Curves of load-displacement (axial compression ratio 0.4). Load / KN Displacement / mm Corrosion rate of steel reinforcement 0 Corrosion rate of steel reinforcement 2% Corrosion rate of steel reinforcement 5% Corrosion rate of steel reinforcement 10% Corrosion rate of steel reinforcement 15% 0 10 20 30 40 4 8 16 12 Figure 10: Curves of load-displacement (axial compression ratio 0.6). It can be seen from the above figures that, bearing capacity and ultimate displacement of joints shows a decreasing tendency when axial compression ratio is the same and corrosion rate of steel reinforcement becomes higher; when corrosion rate of steel reinforcement is 2%, bearing capacity and ultimate displacement degenerates insignificantly; when it is 5%, the degeneration is quite obvious; bearing capacity and displacement have little differences when corrosion rate is 10% and 15%, but ultimate displacement degenerates for 50%. Under the same axial compression ratio, load-displacement curves partially coincide before yield point, suggesting corrosion rate of steel reinforcement has no influence on component when beam end shoulder small load. But with the increase of external load, bearing capacity of component declines. When corrosion rate is 10% and 15% particularly, protective layer cracks, which accelerates corrosion of steel reinforcement and severely influence mechanical performance of steel reinforcement and coordinated working between steel reinforcement and concrete. Table 2 shows how corrosion rate influences ultimate bearing capacity and displacement of reinforced concrete framework joints when axial compression ratio is 0.2.