报告题目：Understanding of Relationships among Chemistry, Microstructure, and Mechanical Properties of Stone-based Infrastructure Materials
报告嘉宾：Mingjiang Tao, Worcester Polytechnic Institute
Mingjiang Tao received BS in civil engineering from Fuzhou University, China in 1997 and a MS in geotechnical enigneering from Tongji University, China in 2000, and Ph.D. in civil engineering from Case Wester Reserve University, USA, in 2003, respectively. He joined Worcester Polytechnic Institute in 2007, where he is an Associate Professor. He is the author of more than 56 papers on alternative cementitious binders, asphlat concrete, granular materials, and characterization of construction materials at nano- and marco-scales. Dr. Tao’s current research interests lie primarily in developing smart and multifunctional civil engineering materials, with the aid of emerging technologies, such as additive manufacturing, data science, biomimetics, and materials science. His research has been funded by the National Science Foundation, Federal Highway Administration, state departments of transportation, and New England Transportation Consortium. Prof. Tao is a Member of the American Society of Civil Engineers and member of Chemical and Mechanical Stabilization Committee (AFS90), Engineering Behavior of Unsaturated Soils Committee, and Physicochemical and Biological Processes in Soils (AFP40) of the Transportation Research Board, and member of Sigma Xi.
Stone-based infrastructure materials, such as cement and asphalt concretes, are widely used in various civil engineering applications, which have a similar material structure that includes an aggregate skeleton and a binding medium. Binding agents, acting as a glue that binds all aggregates together, play a crucial role in overall performance of stone-based materials. However, our understanding about these binding agents remains poor or limited. In this talk, I will share some results from our research efforts that aim to fill the knowledge gap in the chemical-microstructure-mechanical link of two binding agents: 1. Organic asphalt binder; and 2. Inorganic geopolymer. Their microscopic morphology and mechanical contrast among the multiphase features were evaluated using scanning electronic microscopy (SEM), atomic force microscopy (AFM) and nanoindentation, while their bulk thermal and mechanical properties were investigated with modulated differential scanning calorimetry (MDSC), a dynamic shear rheometer (DSR), and unconfined compressive strength testing, respectively. These findings enhance our understanding of the complicated relationships among chemistry, microstructure, and mechanical properties of binding agents, which would enable us to develop materials with desired properties by tailoring their chemistry.