CAREER: Model-Based Microstructure Evaluation of Hydrating Cementitous Materials: Development of a Test System and Experimental Investigation

Cuny City College, New York NY

Investigators

Abstract

Requirement of high performance concrete places high demands on achieving superior performance in both strength and durability. Producing these new, engineered concretes often involves improving the microstructure of the cementitous phase of the concrete to achieve the desired properties. Successful production of high-performance concrete generates research needs in the following areas: (a) developing methods to monitor and assess the microstructure, and (b) developing a fundamental understanding of the relationship between the microstructure of the cementitous phase and the strength and durability characteristics of the concrete. Techniques that provide for assessing the internal structure of the cementitous phase and a rational way of predicting the development of its material properties are required. Sustaining high level of research activity in universities requires the enthusiastic participation of students. Therefore scientific achievements have to be concordant with advancements in education and outreach. In academia there is a need to provide an environment conducive to learning. In particular, an environment that increases the participation of minority students in engineering practice and research is required. There is a need for better outreach to the minority students and increasing their involvement in research related activities. This career plan addresses the dual objectives: (a) advance the state-of-the-art in monitoring the microstructure development in cementitous systems and (b) provide for increased participation of minority students in research related activities. An essential aspect of the study is the educational and professional development of not only the Principal Investigator, but also the student participants and collaborators from engineering practice. This research plan will commence with the development of an ultrasonic test procedure for obtaining the acoustic properties of hydrating cementitous systems. The two main components are: (a) to relate the acoustic properties with information pertaining to microstructure of a hydrating cementitous system, and (b) to provide a rational approach for predicting property development in these materials. The model-based representation of the cement microstructure will be formulated using the poroelastic theory.Fundamental understanding of the relationship between the internal structure variables within the framework of the poroelastic theory and the properties of cement systems (such as elastic moduli, strength, shrinkage etc.) will be researched. Finally, microstructure-based predictive approaches for property development will be developed. The proposed multi-disciplinary research approach involves developing collaborations with the departments of Chemistry, Electrical, and Computer Engineering. The research tasks involve synthesizing the knowledge and understanding developed in these areas. Minority student participation throughout the course of this study will be enacted at the graduate, undergraduate and high school levels. The participating students will be better prepared for further study or for practice and, it is hoped, will be excited by the challenging nature of the research. Educational outreach is specifically targeted at women minority high schools students in the Harlem area of New York City with the objective of increasing their enrollment in the engineering program at the City College of New York (CCNY). Dissemination of the study results to more distant researchers will be achieved through publishing of the results and participating in international collaborative studies. In addition, the development of an innovative web-based virtual laboratory is an essential component of this study.s educational component.