纳米材料改性再生自密实混凝土多重界面性能

Multiple Interfacial Performance of Recycled Self-Compacting Concrete Modified by Nanomaterials

摘要:

将纳米CaCO3和纳SiO2掺入再生骨料自密实混凝土（RASCC）中，通过纳米压痕技术研究其多重界面性能，并探讨RASCC微观性能与宏观力学性能之间的关系.结果表明，掺入纳米CaCO3与纳米SiO2可有效提升RASCC的多重界面性能，改善ITZ2与ITZ3的微观结构与界面模量，提升RASCC的抗压强度与弹性模量，其中纳米SiO2的改性效果更显著.掺量为1.0 %时，各项力学性能达到最大值，进一步增加掺量则因颗粒团聚而性能下降.纳米SiO2改性后，ITZ3界面模量与抗压强度、弹性模量存在显著相关性，宏观力学性能随着界面模量的增加先增大后减小.

Abstract:

Nano-CaCO3 and nano-SiO2 were incorporated into recycled aggregate self-compacting concrete (RASCC) to investigate the multiple interfacial properties by nanoindentation technique and to explore the relationship between the microscopic properties and macroscopic mechanical properties of RASCC. The results show that the incorporation of nano-CaCO3 and nano-SiO2 can effectively improve the multiple interfacial properties of RASCC, improve the microstructure and interfacial modulus of ITZ2 and ITZ3, and increase the compressive strength and modulus of elasticity of RASCC, with the modification effect of nano-SiO2 being more significant. The mechanical properties of RASCC were maximized at a doping level of 1.0 %, and decreased due to the agglomeration of the particles when the doping level was further increased. After nano-SiO2 modification, there is a significant correlation between ITZ3 interfacial modulus and compressive strength and elastic modulus, and the macroscopic mechanical properties increase and then decrease with the increase of interfacial modulus.