钢-聚丙烯混杂纤维混凝土多尺度本构关系: 从纳米尺度到宏观尺度

项目名称： 钢-聚丙烯混杂纤维混凝土多尺度本构关系: 从纳米尺度到宏观尺度

项目编号： No.51478367

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 建筑环境与结构工程学科

项目作者： 徐礼华

作者单位： 武汉大学

项目金额： 85万元

中文摘要： 借鉴前人研究成果，通过纳米压痕试验、纤维拔出试验分别测得水泥基纳米压痕力-压深关系曲线、纤维与水泥基的拔出力-位移关系等，运用SEM扫描电镜和TEM透射电镜试验技术，构建混杂纤维混凝土内部纳观及微细观结构拓扑表征；基于微细观力学和均匀化理论，研究不同纤维复合材料基体的开裂、纤维与基体的界面脱粘、纤维拔出或拉断、界面本构模型等，建立宏观应力应变与纳米尺度及微细观尺度信息之间的联系，提出如下预期成果:(1)水泥基纳米硬度、纳米模量以及分子接触本构模型;(2)纤维拔出破坏机理、纤维/水泥基界面粘结强度及其粘结-滑移本构模型;(3)混杂纤维混凝土各相颗粒之间局部微观接触本构模型及计算程序;(4)混杂纤维混凝土的纳观及微细观结构几何拓扑表征及多尺度本构关系。研究成果有助于揭示混杂纤维混凝土材料损伤失效的内在本质，并为修订《纤维混凝土结构技术规程》(CECS38:2004)的条文提供理论支撑和试验依据

中文关键词： 混杂纤维混凝土；多尺度；纳米压痕试验；纤维拔出试验；接触本构模型

英文摘要： On the basis of the research findings reported in the literature, this research proposal seeks to: (i) Develop the bond-slip contact model by means of nanoindentation and filament pull-out tests; (ii) Construct the microstructure of steel-polypropylene hybrid fiber-reinforced concrete using SEM and TEM techniques; (iii) Investigate the micromechanical phenomena of steel-polypropylene hybrid fiber-reinforced concrete as well as the microscale interactions between the fiber and the cement paste; and (iv) Establish the stress-strain relationship for steel-polypropylene hybrid fiber-reinforced concrete at both the nano-scopic and macroscopic levels. Accordingly, this study will consist of the following steps: (i) Investigate the nanoscopic hardness and modulus as well as the molecular-scale contact constitutive model for steel-polypropylene hybrid fiber-reinforced concrete materials; (ii) Determine the pull-out failure mechanism of filaments and the fiber-cement interfacial bond strength and establish the relevant bond-slip model; (iii) Develop the microscopic particle-to-particle contact model; and (iv) Characterize the topological nanostructure of steel-polypropylene hybrid fiber-reinforced concrete and the macroscopic constitutive model. Based on the research results, this research will lead to a better understanding of the damage and failure mechanism of and provide the theoretical methodology and framework for formulating the Building Code CECS38:2004.

英文关键词： Steel-Polypropylene Hybrid Fiber-Reinforced Concrete;Multiscale Modeling;Nanoindentation;Filament Pull-out Test;Contact Relationship