With the increasingly severe impact of air pollution on buildings and residential environments,TiO2 photocatalytic cement-based materials have received widespread attention.Photocatalytic high ductility cement-based materials(PC-ECC)were pre-pared using TiO2 nanoparticles as photocatalysts,and their mechanical and photocatalytic properties under uniaxial tensile stress were researched.The mechanism of TiO2 nanoparticles on the ductility of PC-ECC by combining micro mechanical models and pore structure analysis was analyzed.The results showed that PC-ECC doped with 0～15％TiO2 nanoparticles exhibited significant strain hardening characteristics and excellent multi crack cracking ability at 28 days of age.The tensile strain reached its lowest value of 3.48％when doped with 1％TiO2 nanoparticles,and then increased to 4.55％.The trend of macroscopic tensile strain variation with TiO2 nanoparticle content is consistent with the strain hardening index J'b/Jtip,and the latter is closely related to mi-crostructure such as pore structure.After 72 hours of UV irradiation,the photocatalytic degradation efficiency of methylene blue in PC-ECC doped with 5％TiO2 nanoparticles reached 95％,which conforms to the first-order reaction kinetics model.
关键词
高延性水泥基材料/TiO2/拉伸性能/纤维/基质界面/应变硬化
Key words
high ductility cement-based materials/TiO2/tensile properties/fiber/matrix interface/strain hardening
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