侵蚀条件下天然橡胶桥梁支座胶料拉伸性能的研究

针对天然橡胶(NR)桥梁支座的使用条件,研究在冻融、盐冻、热老化以及强酸腐蚀条件下NR桥梁支座胶料的拉伸性能。结果表明:随着冻融次数的增加,胶料的拉伸应力下降,但降幅不大,抗冻融能力较强;经过60次盐冻循环后,胶料的最大拉伸应力下降4.1%,抗盐冻能力较强;随着热老化时间的延长,胶料的拉伸应力下降幅度较大,在湿热环境中应加强NR桥梁支座的热老化防护;经过强酸腐蚀后,胶料的拉伸应力下降幅度较大,经硝酸、硫酸和亚硝基硫酸分别腐蚀60 d后,胶料的最大拉伸应力分别降低16.2%,17.2%和14.1%。

Study on Tensile Properties of Natural Rubber Bearing under Erosion Condition

According to the service conditions of natural rubber(NR)bridge bearing,the tensile properties of NR bridge bearing compound under the conditions of freeze-thawing cycle,salt freezing,thermal aging and strong acid corrosion were studied.The results showed that,with the increase of the number of freeze-thawing cycles,the tensile stress of the compound decreased,but the decline was small,showing that the compound had relatively strong freeze-thawing resistance.After 60 salt freezing cycles,the maximum tensile stress of the compound decreased by 4.1%,indicating the compound had strong salt freezing resistance.However,with the extension of the thermal aging time,the tensile stress of the compound decreased greatly.The thermal aging protection of the NR bridge bearing used in the hot-humid enviroment needed to be improved.After strong acid corrosion,the tensile stress of the compound decreased greatly.Specifically,after being corroded by nitric acid,sulfuric acid and nitric sulfuric acid for 60 days,the maximum tensile stress decreased by 16.2%,17.2%and 14.1%respectively.