混凝土气体渗透模拟研究  

Study on Simulation of Gas Permeation in Concrete

作　　者：宋杨[1] 陈望 李俊锋 李金远 吴海洋 SONG Yang;CHEN Wang;LI Junfeng;LI Jinyuan;WU Haiyang(School of Civil Engineering and Architecture, Changzhou Institute of Technology, Changzhou 213032)

机构地区：[1]常州工学院土木建筑工程学院,江苏常州213032

出　　处：《常州工学院学报》2021年第4期1-7,共7页Journal of Changzhou Institute of Technology

基　　金：国家自然科学基金项目(51708049);江苏省自然科学青年基金项目(BK20170293);江苏高校“青蓝工程”资助(苏教师函〔2020〕10号)。

摘　　要：采用聚焦离子束/扫描电镜(FIB/SEM)技术对混凝土中的硬化水泥浆体进行扫描,并基于试件三维孔隙结构,分别采用逾渗孔隙结构模型和计算流体力学对试件进行渗透率模拟分析。结果表明:至少3个FIB/SEM观测试件才能够具有硬化水泥浆体孔隙率的表征单元性;基于逾渗孔隙网络模型,试件的渗透率预测结果表现出较为明显的各向异性,其在X方向和Y方向的渗透率均较小,为3.40×10^(-19)~5.65×10^(-19) m^(2),而在Z方向其渗透率均有较大提升,增大至12.42×10^(-19)~13.82×10^(-19) m^(2);流体力学的渗透率计算结果较逾渗孔隙网络模型更大,为13.09×10^(-19)~99.91×10^(-19) m^(2),这是由于逾渗孔隙网络模型对原始孔隙结构进行了简化处理,势必会导致试件孔隙结构通过能力小于原始试件,故其渗透率也较小。Focused Ion Beam/Scanning Electron Microscopy(FIB/SEM)is used to scan the hardened cement paste in concrete.Based on the 3D pore structure,Percolation-Pore Network Model(PPNM)and Computational Fluid Dynamics(CFD)are respectively used to simulate the permeability of the samples.Results show that at least three FIB/SEM samples are needed to characterize the porosity of hardened cement paste.The permeabi-lity prediction results based on PPNM show obvious anisotropy in the samples.The permeability in both X direction and Y direction is relatively small,in the range of 3.40×10^(-19) to 5.65×10^(-19) m^(2),while the permeability in Z direction increases considerably to 12.42×10^(-19)~13.82×10^(-19) m^(2).The permeability by CFD is even larger than that by PPNM,which is 13.09×10^(-19)~99.91×10^(-19) m^(2).This is because PPNM simplifies the original pore structure,which inevitably leads to the smaller permeation capacity of the pore structure of the samples compared with that of the original samples,thus resulting in comparatively smaller permeability.

关 键 词：混凝土 气体渗透率 表征单元体 逾渗孔隙网络模型 计算流体力学 

分 类 号：TU528[建筑科学—建筑技术科学]