Identification and Modeling of Interphase in Cementitious Mixtures through Integrated Experimental-Computational Multiscale Approach

通过综合实验计算多尺度方法识别和建模水泥混合物中的界面

• 批准号: 1635055
• 负责人: Yong-Rak Kim
• 金额: $ 25.94万
• 依托单位: University of Nebraska-Lincoln
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-08-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1635055&HistoricalAwards=false
• 关键词: Identification; Modeling; Interphase; Cementitious; Mixtures

Effective properties and structural performance of cementitious mixtures are substantially governed by the quality of the interphase region, because it acts as a bridge transferring forces between aggregates and a binding matrix, and is generally susceptible to damage. In spite of advancements made over the last several decades, understanding and modeling the interfacial region of cementitious mixtures still presents important challenges. As non-traditional additives such as recycled aggregates and alternative binding agents are more often used today, there is a growing need of fundamental knowledge to uncover interphase formation mechanisms and a resulting model to predict interphase properties. The goal of this research is to develop an experimental-computational method to identify and model the interphase region of cementitious materials. The successful application and dissemination of research findings is expected to significantly reduce costs, natural resources, and carbon dioxide emissions through the promotion of non-cement binding agents and secondary aggregates without compromising mechanical properties and structural performance. This project will improve education and training opportunities of underrepresented students and also impact current civil engineering practices, allowing for the development of more cost-effective mixture products that significantly increase the performance and sustainability of a wide range of structural materials.To meet the goal, this research systematically integrates multiscale tests and the two-way coupled multiscale computational modeling with the following four specific objectives: 1) develop a multiscale experimental method to identify microstructure details and properties of the interphase zone in cementitious mixtures; 2) develop a two-way coupled computational multiscale model that involves nonlinear-inelastic material behavior; 3) integrate the experimental efforts with computational modeling to determine effective material properties of interphase region; and 4) validate-calibrate the modeling approach and extend it to other cases where mixture design variables are varied. This research will advance the fundamental understanding of cementitious mixtures, specifically the mechanical effects of interphase on entire mixture properties and performance. This research incorporates several intellectual significances including micromechanical-nanomechanical material characterization in multiple length-time scales and the two-way linked multiscale computation with nonlinear-inelastic material behavior. Successful completion of the project will provide significant key information that will advance current technology and knowledge on a broad range of multiphase particulate solids in which inelastic-nonlinear deformation, interface, and multiphysical loads are involved as primary energy dissipation and performance-controlling phenomena.

水泥混合物的有效性能和结构性能基本上取决于相间区域的质量，因为它充当骨料和粘合基质之间传递力的桥梁，并且通常容易受到损坏。尽管在过去几十年中取得了进步，但对水泥混合物界面区域的理解和建模仍然面临着重要的挑战。随着如今越来越多地使用再生骨料和替代粘合剂等非传统添加剂，越来越需要基础知识来揭示界面形成机制和预测界面特性的模型。本研究的目标是开发一种实验计算方法来识别和模拟胶凝材料的界面区域。研究成果的成功应用和传播预计将通过推广非水泥粘结剂和二次骨料，在不影响机械性能和结构性能的情况下，显着降低成本、自然资源和二氧化碳排放。该项目将改善代表性不足的学生的教育和培训机会，并影响当前的土木工程实践，从而开发更具成本效益的混合物产品，显着提高各种结构材料的性能和可持续性。为了实现这一目标，本研究系统地集成了多尺度测试和双向耦合多尺度计算建模，具有以下四个具体目标：1）开发多尺度实验方法来识别微观结构细节和 水泥混合物中相间区域的特性； 2）开发涉及非线性非弹性材料行为的双向耦合计算多尺度模型； 3）将实验工作与计算模型相结合，以确定相间区域的有效材料特性； 4) 验证校准建模方法并将其扩展到混合设计变量变化的其他情况。这项研究将增进对水泥混合物的基本理解，特别是界面对整个混合物特性和性能的机械影响。这项研究具有多种智力意义，包括多个长度时间尺度的微机械-纳米机械材料表征以及非线性-非弹性材料行为的双向链接多尺度计算。该项目的成功完成将提供重要的关键信息，从而推动当前广泛的多相颗粒固体的技术和知识，其中非弹性非线性变形、界面和多物理载荷作为主要的能量耗散和性能控制现象。

项目成果

An integrated microstructural-nanomechanical-chemical approach to examine material-specific characteristics of cementitious interphase regions

• DOI: 10.1016/j.matchar.2018.01.045
• 发表时间: 2018-04-01
• 期刊: MATERIALS CHARACTERIZATION
• 影响因子: 4.7
• 作者: Khedmati, Mandieh;Kim, Yong-Rak;Nguyen, Charles
• 通讯作者: Nguyen, Charles

Two-Way Linked Multiscale Method Integrated with Nanomechanical Tests and Cohesive Zone Fracture to Model Highly Heterogeneous Binding Materials

双向关联多尺度方法与纳米力学测试和内聚区断裂相结合，用于模拟高度异质粘合材料

• DOI: 10.1061/(asce)em.1943-7889.0001518
• 发表时间: 2018
• 期刊: Journal of Engineering Mechanics
• 影响因子: 3.3
• 作者: Rami, Keyvan Zare;Kim, Yong-Rak;Khedmati, Mahdieh;Nsengiyumva, Gabriel;Alanazi, Hani
• 通讯作者: Alanazi, Hani

Effects of Na2O/SiO2 molar ratio on properties of aggregate-paste interphase in fly ash-based geopolymer mixtures through multiscale measurements

• DOI: 10.1016/j.conbuildmat.2018.10.024
• 发表时间: 2018-12-10
• 期刊: CONSTRUCTION AND BUILDING MATERIALS
• 影响因子: 7.4
• 作者: Khedmati, Mandieh;Alanazi, Hani;Moussavi, Sussan
• 通讯作者: Moussavi, Sussan

Effect of slag, silica fume, and metakaolin on properties and performance of alkali-activated fly ash cured at ambient temperature

• DOI: 10.1016/j.conbuildmat.2018.11.172
• 发表时间: 2019-02-10
• 期刊: CONSTRUCTION AND BUILDING MATERIALS
• 影响因子: 7.4
• 作者: Alanazi, Hani;Hu, Jiong;Kim, Yong-Rak
• 通讯作者: Kim, Yong-Rak

Investigation of the interphase between recycled aggregates and cementitious binding materials using integrated microstructural-nanomechanical-chemical characterization

• DOI: 10.1016/j.compositesb.2018.09.041
• 发表时间: 2019-02-01
• 期刊: COMPOSITES PART B-ENGINEERING
• 影响因子: 13.1
• 作者: Khedmati, Mandieh;Kim, Yong-Rak;Turner, Joseph A.
• 通讯作者: Turner, Joseph A.