Committee Chair

Wu, Weidong

Committee Member

Fomunung, Ignatius; Owino, Joseph; Onyango, Mbakisya A.

Department

Dept. of Engineering

College

College of Engineering and Computer Science

Publisher

University of Tennessee at Chattanooga

Place of Publication

Chattanooga (Tenn.)

Abstract

Crushing concrete to bring the aggregates back to be used for concrete structures is a process of creating recycled aggregate (RA). Recycled aggregate concrete (RAC) has become increasingly important in the field of construction. The use of recycled aggregate concrete made from recycled aggregate in civil engineering construction projects such as highways will provide both economic and environmental benefits in the near future. Achieving environmental sustainability will enable the Earth’s construction materials to support our future generations. Unfortunately, massive usage of RAC in the USA is not satisfying, even through the aging transportation infrastructure will inevitably produce tremendous amounts of waste concrete. Concrete structures or pavements generally suffer from the crack problem. The morphology and growth process of cracks, most importantly, how these factors affect the concrete structure, is of great significance. The study of RAC is thus considerably needed to encourage the application of RAC. Crack modeling may lead to improved recycled aggregate concrete. In this work, extended finite element approach and concrete damage plasticity material models are employed to predict the failure of recycled aggregate concrete. The recycled aggregate concrete was modeled based on a realistic concrete model with randomly distributed recycled aggregates. The arbitrary shapes of aggregates, and the new and old interfacial transition zones are constructed by using Fourier series. Recycled aggregate concrete models with or without initial crack are investigated. Results of using an extended finite element with both linear elastic fracture mechanics and cohesive segment approaches are discussed as well.

Acknowledgments

I would like to thank my committee members who have generously granted me their expertise and precious time. I would like to give a special thanks to my advisor Dr. Weidong Wu, for his tons of hours of guidance, reading, encouragement, and patience through the whole process. Thank you Dr. Joseph Owino, Dr. Ignatius Fomunung, and Dr. Mbakisya A. Onyango for agreeing to serve as my committee. Thank you to the Department of Civil Engineering at UTC, and all the staff and faculty. I would like to thank my family members who supported my academic career. Thank you to my father and mother for everything you have done. You gave me a great support during my school life at the University of Tennessee at Chattanooga. I would like to thank those who have contributed to this thesis, those who prayed for me and those who encouraged me to achieve success in this thesis. I would like to especially thank Mr. George Chen and Mrs. Vicky Chen and their family, Mr. Phil Reifinger and Mrs. Jean Reifinger and their family, Mr. Mike Lapihuska and Mrs. Dee Lapihuska and their family, for their encouragement and prayers.

Degree

M. S.; A thesis submitted to the faculty of the University of Tennessee at Chattanooga in partial fulfillment of the requirements of the degree of Master of Science.

Date

5-2016

Subject

Aggregates (Building materials) -- Testing; Concrete -- Additives

Keyword

XFEM, concrete damage plasticity, recycled aggregate concrete,crack

Document Type

Masters theses

Extent

xii, 49 leaves

Language

English

Rights

Under copyright.

License

http://creativecommons.org/licenses/by-nc-nd/3.0/

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