聚氨酯混凝土力学性能温度响应及机理  

Temperature response and mechanism of mechanical properties of polyurethane concrete

作　　者：元强[1,2] 李海洋 郑新国[3] 谭社会 谢宗霖 Yuan Qiang;Li Haiyang;Zheng Xinguo;Tan Shehui;Xie Zonglin(School of Civil Engineering,Central South University,Changsha 410075,China;National Engineering Research Center of High-Speed Railway Construction Technology,Central South University,Changsha 410075,China;Railway Engineering Research Institute,China Academy of Railway Sciences Co.,Ltd.,Beijing 100081,China;China Railway Shanghai Group Co.,Ltd.,Shanghai 200071,China)

机构地区：[1]中南大学土木工程学院,长沙410075 [2]中南大学高速铁路建造技术国家工程研究中心,长沙410075 [3]中国铁道科学研究院集团有限公司铁道建筑研究所,北京100081 [4]中国铁路上海局集团有限公司,上海200071

出　　处：《东南大学学报（自然科学版）》2024年第6期1346-1353,共8页Journal of Southeast University：Natural Science Edition

基　　金：中国国家铁路集团有限公司科技研究开发计划资助项目(L2023G003);国家自然科学基金面上资助项目(52378278)。

摘　　要：研究了聚氨酯混凝土在-25~75℃温度区间的静态和动态力学性能,并采用电子背散射成像和红外吸收光谱研究聚氨酯混凝土力学性能的温度影响机理.结果表明,高温明显降低了聚氨酯混凝土的抗压、抗拉强度和弹性模量,在25~50℃力学性能变化最为显著,轴心抗压强度与弹性模量分别降低超30MPa和1个数量级,因为聚氨酯在该温度区间发生了玻璃态到黏弹态的转变.此外,聚氨酯混凝土的动态力学性能具有频率依赖性,频率从10 Hz提高到120 Hz时,玻璃化转变温度从66.51℃升高到74.41℃.红外光谱验证了氢键化官能团随温度升高而逐渐减弱,表明聚氨酯内部氢键逐渐解离,软硬段微相分离程度降低.The static and dynamic mechanical properties of polyurethane concrete were studied in the temperature range of-25-75℃.Electron backscatter diffraction(EBSD)and Fourier-transform infrared spectroscopy(FT-IR)were used to study the influence of temperature on the mechanical properties of polyurethane concrete.The results indicate that elevated temperatures significantly reduce the compressive strengths,tensile strengths,and the elastic modulus of polyurethane concrete.The most notable changes in mechanical properties occur between 25℃and 50℃,where both the axial compressive strength and elastic modulus experience reductions exceeding 30 MPa and an order of magnitude,respectively.It is attributed to the transition of polyurethane from a glassy state to a viscoelastic state within this temperature range.Additionally,the dynamic mechanical properties of polyurethane concrete exhibit frequency dependence.When the frequency is increased from 10 Hz to 120 Hz,the glass transition temperature rises from 66.51℃to 74.41℃.The FT-IR test confirms that hydrogen-bonded functional groups gradually weaken as the temperature increases,indicating a progressive dissociation of internal hydrogen bonds in polyurethane.This leads to a decreased degree of micro-phase separation between the soft and hard segments.

关 键 词：无砟轨道 聚氨酯混凝土 力学性能 温度响应 

分 类 号：TU528[建筑科学—建筑技术科学]