为更好地研究硅灰对水泥胶砂耐硫酸侵蚀性能的影响,本文将硅灰按不同配合比进行试验,将水泥胶砂置于pH=1的硫酸侵蚀环境中。通过探究试样的外观、质量损失率、抗压强度损失率、硫酸侵蚀下的生成物、微观结构,并结合相关理论分析了硅灰...为更好地研究硅灰对水泥胶砂耐硫酸侵蚀性能的影响,本文将硅灰按不同配合比进行试验,将水泥胶砂置于pH=1的硫酸侵蚀环境中。通过探究试样的外观、质量损失率、抗压强度损失率、硫酸侵蚀下的生成物、微观结构,并结合相关理论分析了硅灰对水泥胶砂抗硫酸侵蚀作用的影响。实验研究表明:随着硅灰掺量的增加,水泥胶砂的抗硫酸侵蚀能力增强,XRD(x-ray diffraction)衍射表明,在硫酸侵蚀下表面生成物为二水石膏(CaSO_(4)·2H_(2)O),反应时会消耗Ca(OH)_(2),同时也会产生一定的体积膨胀;SEM(scanning electron microscope)检测表明,掺入硅灰可以提高试样的密实度,从而提高水泥胶砂的抗硫酸侵蚀性能。从宏观和微观角度综合来看,硅灰掺量为15%时的抗硫酸侵蚀性能最好。展开更多
This paper conducted experimental studies on the damping and mechanical properties of carbon nanotube-nanosilica-cement composite materials with different carbon nanotube contents. The damping and mechanical propertie...This paper conducted experimental studies on the damping and mechanical properties of carbon nanotube-nanosilica-cement composite materials with different carbon nanotube contents. The damping and mechanical properties enhancement mechanisms were analyzed and compared through the porosity structure test, XRD analysis, and scanning electron microscope observation. The results show that the introduction of nanosilica significantly improves the dispersion of carbon nanotubes in the cement matrix. At the same time, the addition of nanosilica not only effectively reduces the critical pore size and average pore size of the cement composite material, but also exhibits good synergistic effects with carbon nanotubes, which can significantly optimize the pore structure. Finally, a rationalization suggestion for the co-doping of nanosilica and carbon nanotubes was given to achieve a significant increase in the flexural strength, compressive strength and loss factor of cement-based materials.展开更多
In the current work concrete mixes containing(7.0-33.11)weight%silica fume as fractional substitution of cement with water/cement ratio(0.42-0.48)were formulated conferring to an implemented two factorial central comp...In the current work concrete mixes containing(7.0-33.11)weight%silica fume as fractional substitution of cement with water/cement ratio(0.42-0.48)were formulated conferring to an implemented two factorial central composite design.The samples were water cured for 7,28,56,and 90 days.The samples were tested for compressive strength and density.The experimental results approved that compressive strength and density increase with age and with rising silica fume content up to 11.9 wt.%.Response surface analysis results for samples cured for 28 days confirmed that silica fume concrete with developed compressive strength(53.42 MPa)could be prepared by incorporation of 11.9 wt.%silica fume as a substituent for cement using a 0.42 water/cement ratio.An intensification in compressive strength and density(up to 39.3%and 2.6%)respectively was recorded for silica fume concrete mixes in contrast to Portland cement concrete.Overall,the research findings revealed that silica fume concretes prepared with appropriate silica fume content and water/cement ratio exhibited superior strength and density features candidate them to be used effectively in civil engineering structural applications.展开更多
文摘为更好地研究硅灰对水泥胶砂耐硫酸侵蚀性能的影响,本文将硅灰按不同配合比进行试验,将水泥胶砂置于pH=1的硫酸侵蚀环境中。通过探究试样的外观、质量损失率、抗压强度损失率、硫酸侵蚀下的生成物、微观结构,并结合相关理论分析了硅灰对水泥胶砂抗硫酸侵蚀作用的影响。实验研究表明:随着硅灰掺量的增加,水泥胶砂的抗硫酸侵蚀能力增强,XRD(x-ray diffraction)衍射表明,在硫酸侵蚀下表面生成物为二水石膏(CaSO_(4)·2H_(2)O),反应时会消耗Ca(OH)_(2),同时也会产生一定的体积膨胀;SEM(scanning electron microscope)检测表明,掺入硅灰可以提高试样的密实度,从而提高水泥胶砂的抗硫酸侵蚀性能。从宏观和微观角度综合来看,硅灰掺量为15%时的抗硫酸侵蚀性能最好。
文摘This paper conducted experimental studies on the damping and mechanical properties of carbon nanotube-nanosilica-cement composite materials with different carbon nanotube contents. The damping and mechanical properties enhancement mechanisms were analyzed and compared through the porosity structure test, XRD analysis, and scanning electron microscope observation. The results show that the introduction of nanosilica significantly improves the dispersion of carbon nanotubes in the cement matrix. At the same time, the addition of nanosilica not only effectively reduces the critical pore size and average pore size of the cement composite material, but also exhibits good synergistic effects with carbon nanotubes, which can significantly optimize the pore structure. Finally, a rationalization suggestion for the co-doping of nanosilica and carbon nanotubes was given to achieve a significant increase in the flexural strength, compressive strength and loss factor of cement-based materials.
文摘In the current work concrete mixes containing(7.0-33.11)weight%silica fume as fractional substitution of cement with water/cement ratio(0.42-0.48)were formulated conferring to an implemented two factorial central composite design.The samples were water cured for 7,28,56,and 90 days.The samples were tested for compressive strength and density.The experimental results approved that compressive strength and density increase with age and with rising silica fume content up to 11.9 wt.%.Response surface analysis results for samples cured for 28 days confirmed that silica fume concrete with developed compressive strength(53.42 MPa)could be prepared by incorporation of 11.9 wt.%silica fume as a substituent for cement using a 0.42 water/cement ratio.An intensification in compressive strength and density(up to 39.3%and 2.6%)respectively was recorded for silica fume concrete mixes in contrast to Portland cement concrete.Overall,the research findings revealed that silica fume concretes prepared with appropriate silica fume content and water/cement ratio exhibited superior strength and density features candidate them to be used effectively in civil engineering structural applications.
