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 view of the disadvantage that the mechanical properties of cement-based composites can be significantly reduced by incorporating waste rubber powder in situ, the surface modification methods of the original rubber ...In view of the disadvantage that the mechanical properties of cement-based composites can be significantly reduced by incorporating waste rubber powder in situ, the surface modification methods of the original rubber powder by coupling agent KH560, sodium hydroxide, polyvinyl alcohol (PVA), methyl hydroxyethyl cellulose ether (MHEC) and tetraethyl orthosilicate (TEOS) as precursors were adopted respectively. The modification of waste rubber powder was studied by Change rate of mortar strength of cement-based composite mortar mixed with waste rubber powder. The results show that the hybrid modification method using tetraethyl orthosilicate as precursor has better ef-fect. When 5 phr ethyl orthosilicate is added, the compressive strength and flexural strength of cement-based composite mortar can be increased by 31.7% and 28%. Scanning electron microscopy (SEM) results show that the surface of waste rubber powder with good modification effect has many pro-trusions and flake-like porous structures which are beneficial to its bonding with cement-based materials.展开更多
Polypropylene fibres and three sizes of steel fibres reinforced concrete are discussed. The total fibres content ranges from 0 4%-0 95% by volume of concrete. A four point bending test is adopted on the notched pris...Polypropylene fibres and three sizes of steel fibres reinforced concrete are discussed. The total fibres content ranges from 0 4%-0 95% by volume of concrete. A four point bending test is adopted on the notched prisms with the size of 100?mm×100?mm×500?mm to investigate the effect of hybrid fibres on crack arresting. The research results show that there is a positive synergy effect between large steel fibres and polypropylene fibres on the load bearing capacity in the small displacement range. But this synergy effect disappears in the large displacement range. The large and strong steel fibre is better than soft polypropylene fibre and small steel fibre in the aspect of energy absorption capacity in the large displacement range. The static usage limitation for the hybrid fibres concrete with “wide peak' or “multi peaks' load CMOD pattern should be carefully selected. The ultimate load bearing capacity and the crack width or CMOD at this load level should be jointly considered.展开更多
The application of carbon nanomaterials, particularly graphene and carbon nanotubes, in cement-based composites is highly significant. These materials demonstrate the multifunctionality of carbon and offer extensive p...The application of carbon nanomaterials, particularly graphene and carbon nanotubes, in cement-based composites is highly significant. These materials demonstrate the multifunctionality of carbon and offer extensive possibilities for technological advancements. This research analyzes how the integration of graphene into cement-based composites enhances damping and mechanical properties, thereby contributing to the safety and durability of structures. Research on carbon nanomaterials is ongoing and is expected to continue driving innovation across various industrial sectors, promoting the sustainable development of building materials.展开更多
玄武岩纤维(BF)合理的长度及掺量对水泥基复合材料的工作性能及力学性能有显著影响。试验对比研究了长度为3、6、9 mm BF,当掺量为0.2%、0.4%、0.6%、0.8%时,BF水泥基复合材料的流动度及抗折、抗压性能的变化,并探讨了试块在7 d、14 d...玄武岩纤维(BF)合理的长度及掺量对水泥基复合材料的工作性能及力学性能有显著影响。试验对比研究了长度为3、6、9 mm BF,当掺量为0.2%、0.4%、0.6%、0.8%时,BF水泥基复合材料的流动度及抗折、抗压性能的变化,并探讨了试块在7 d、14 d热稳定性能的变化。结果表明,BF越长,掺量越高,BF水泥基复合材料流动度显著下降。与空白试块的流动度267 mm相比,掺0.8%9 mm BF水泥基材料的流动度下降至207 mm。水泥基中加入合理掺量与长度的BF时,能显著提高水泥基复合材料的抗拉、抗压强度。当长度为9 mm BF掺量小于0.4%时,BF水泥基复合材料的抗折、抗压强度综合性能最优。此外,BF水泥基复合材料在7 d和14 d具有类似的热降解行为,且14 d试块的热稳定性优于7 d试块的热稳定性。同样龄期下,与空白试块相比,BF水泥基试块的热稳定性明显提升。展开更多
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 view of the disadvantage that the mechanical properties of cement-based composites can be significantly reduced by incorporating waste rubber powder in situ, the surface modification methods of the original rubber powder by coupling agent KH560, sodium hydroxide, polyvinyl alcohol (PVA), methyl hydroxyethyl cellulose ether (MHEC) and tetraethyl orthosilicate (TEOS) as precursors were adopted respectively. The modification of waste rubber powder was studied by Change rate of mortar strength of cement-based composite mortar mixed with waste rubber powder. The results show that the hybrid modification method using tetraethyl orthosilicate as precursor has better ef-fect. When 5 phr ethyl orthosilicate is added, the compressive strength and flexural strength of cement-based composite mortar can be increased by 31.7% and 28%. Scanning electron microscopy (SEM) results show that the surface of waste rubber powder with good modification effect has many pro-trusions and flake-like porous structures which are beneficial to its bonding with cement-based materials.
文摘Polypropylene fibres and three sizes of steel fibres reinforced concrete are discussed. The total fibres content ranges from 0 4%-0 95% by volume of concrete. A four point bending test is adopted on the notched prisms with the size of 100?mm×100?mm×500?mm to investigate the effect of hybrid fibres on crack arresting. The research results show that there is a positive synergy effect between large steel fibres and polypropylene fibres on the load bearing capacity in the small displacement range. But this synergy effect disappears in the large displacement range. The large and strong steel fibre is better than soft polypropylene fibre and small steel fibre in the aspect of energy absorption capacity in the large displacement range. The static usage limitation for the hybrid fibres concrete with “wide peak' or “multi peaks' load CMOD pattern should be carefully selected. The ultimate load bearing capacity and the crack width or CMOD at this load level should be jointly considered.
文摘The application of carbon nanomaterials, particularly graphene and carbon nanotubes, in cement-based composites is highly significant. These materials demonstrate the multifunctionality of carbon and offer extensive possibilities for technological advancements. This research analyzes how the integration of graphene into cement-based composites enhances damping and mechanical properties, thereby contributing to the safety and durability of structures. Research on carbon nanomaterials is ongoing and is expected to continue driving innovation across various industrial sectors, promoting the sustainable development of building materials.
文摘玄武岩纤维(BF)合理的长度及掺量对水泥基复合材料的工作性能及力学性能有显著影响。试验对比研究了长度为3、6、9 mm BF,当掺量为0.2%、0.4%、0.6%、0.8%时,BF水泥基复合材料的流动度及抗折、抗压性能的变化,并探讨了试块在7 d、14 d热稳定性能的变化。结果表明,BF越长,掺量越高,BF水泥基复合材料流动度显著下降。与空白试块的流动度267 mm相比,掺0.8%9 mm BF水泥基材料的流动度下降至207 mm。水泥基中加入合理掺量与长度的BF时,能显著提高水泥基复合材料的抗拉、抗压强度。当长度为9 mm BF掺量小于0.4%时,BF水泥基复合材料的抗折、抗压强度综合性能最优。此外,BF水泥基复合材料在7 d和14 d具有类似的热降解行为,且14 d试块的热稳定性优于7 d试块的热稳定性。同样龄期下,与空白试块相比,BF水泥基试块的热稳定性明显提升。
