This work focuses on the dynamic rheological behavior of low water-to-binder ratio cement mortars blended with fly ash microspheres（FAM） or silica fume（SF）. The initial slump flow of each group has been controlled...This work focuses on the dynamic rheological behavior of low water-to-binder ratio cement mortars blended with fly ash microspheres（FAM） or silica fume（SF）. The initial slump flow of each group has been controlled at similar values by adjusting the superplasticizer dosages. With the help of a coaxial cylinder rheometer, the dynamic rheological behaviors of these mortars are investigated by frequency sweeping in the range of 0-2 Hz under large amplitude oscillatory shear（LAOS）. Based on the systematical elaboration of dynamic rheological testing theory, the experimental data are processed according to Lissajous plot fitting to reveal the viscoelastic characteristics. The nonlinearity of response signals is further assessed with Fourier transform（FT） analysis. The parameters, storage modulus G＇, loss modulus G＂ and relative amplitude I3/I1 are proposed to clarify the influences of FAM and SF on the stability and energy consumption of local structures and nonlinearity of response torques. The hydration characteristics of various groups well confirmed the rheological phenomenon. This study is beneficial for the preparation and optimization of flow state concrete such as pumping concrete and self-compacting concrete.展开更多
The influence of the condensed structure of poly(styrene-co-acrylonitrile) (SAN) and traces of tetrahydrofuran(THF) that remained in titanyl phthalocyanine (TiOPc)/SAN films after fabrication on the photoconductive st...The influence of the condensed structure of poly(styrene-co-acrylonitrile) (SAN) and traces of tetrahydrofuran(THF) that remained in titanyl phthalocyanine (TiOPc)/SAN films after fabrication on the photoconductive stability ofTiOPc/SAN composites is studied. The results reveal that the existence of traces of THF results in the increase of thephotoconductivity and the charging voltage. The main facors responsible for the unstable photoconductivity of thephotoconductors are believed to be the relaxation of SAN and the slow volatilization of THF.展开更多
基金Fundey by the Major State Basic Research Development Program of China(973 Program)(No.2015CB655101)the National Natural Science Foundations of China(No.51379163)
文摘This work focuses on the dynamic rheological behavior of low water-to-binder ratio cement mortars blended with fly ash microspheres（FAM） or silica fume（SF）. The initial slump flow of each group has been controlled at similar values by adjusting the superplasticizer dosages. With the help of a coaxial cylinder rheometer, the dynamic rheological behaviors of these mortars are investigated by frequency sweeping in the range of 0-2 Hz under large amplitude oscillatory shear（LAOS）. Based on the systematical elaboration of dynamic rheological testing theory, the experimental data are processed according to Lissajous plot fitting to reveal the viscoelastic characteristics. The nonlinearity of response signals is further assessed with Fourier transform（FT） analysis. The parameters, storage modulus G＇, loss modulus G＂ and relative amplitude I3/I1 are proposed to clarify the influences of FAM and SF on the stability and energy consumption of local structures and nonlinearity of response torques. The hydration characteristics of various groups well confirmed the rheological phenomenon. This study is beneficial for the preparation and optimization of flow state concrete such as pumping concrete and self-compacting concrete.
基金This work was supported by the National Science Fund for Distinguished Young Scholars (Grant 50125312), Key Program of the National Natural Science Foundation of China (Grant 50133020) and Special Funds for Major State Basic Research Project. China (Gran
文摘The influence of the condensed structure of poly(styrene-co-acrylonitrile) (SAN) and traces of tetrahydrofuran(THF) that remained in titanyl phthalocyanine (TiOPc)/SAN films after fabrication on the photoconductive stability ofTiOPc/SAN composites is studied. The results reveal that the existence of traces of THF results in the increase of thephotoconductivity and the charging voltage. The main facors responsible for the unstable photoconductivity of thephotoconductors are believed to be the relaxation of SAN and the slow volatilization of THF.
