Experimental study on the effect of alternating ageing and sea corrosion on laminated natural rubber bearing’s tension-shear property

The laminated natural rubber bearings (NRBs) used in offshore or sea-crossing bridges, are subjected to marine environments over an extended period and therefore vulnerable to the effect of alternating ageing and sea corrosion caused by weather conditions such as temperature, rain, sun, sea winds, waves etc. In addition, there are no systematic theories about the tension capability for NRBs now. Therefore, in this paper, the alternating of ageing and sea corrosion test on 12 NRBs was conducted for 60 days to investigate the deterioration trend of its tension shear property with different horizontal shear strains. Test results show that initial tension stiffness, yield stiffness and yield tension stress with different horizontal shear strains, all decrease with the alternating ageing and sea corrosion test time. Further, tension failure stress and strain with 50% and 100% horizontal shear strain, also decreases with the alternating ageing and sea corrosion test time. After testing for 60 days, both the tension failure stress and tension failure strain with 100% horizontal shear strain have the biggest drop. Additionally, only broken rubber is left after NRB failure before and after testing for 60 days.