Graduation Semester and Year

Summer 2025

Language

English

Document Type

Dissertation

Degree Name

Doctor of Philosophy in Civil Engineering

Department

Civil Engineering

First Advisor

Dr. Surendra P. Shah

Second Advisor

Dr. Maria S. Konsta-Gdoutos

Third Advisor

Dr. Melanie L. Sattler

Fourth Advisor

Dr. Yaowu Hao

Fifth Advisor

Dr. Panagiotis Danoglidis

Abstract

The transition of concrete from a fluid to solid state is a critical phase that determines workability, early-age performance, and long-term durability. Electrochemical impedance spectroscopy (EIS) enables continuous monitoring of electrical properties during early-age hydration, offering detailed insights into microstructural development and setting behavior. This thesis introduces an integrated methodology combining adaptive rheology and EIS to monitor the fluid-to-solid transition in cement-based materials during the initial hours of setting. The research examines the microstructural evolution of both plain and blended cement pastes, incorporating chemical additives such as accelerators and retarders, through simultaneous real-time rheological and electrical measurements. Continuous monitoring facilitates the assessment of hydration progression, identification of distinct setting stages, and accurate determination of setting times. Experimental results are compared with setting times obtained from the Vicat needle test. Comparative analysis using heat of hydration as a benchmark across various cementitious mixtures demonstrates that the rate of capacitance measurement provides high sensitivity and reliability, effectively identifying both early and delayed setting trends. The green strength of the material is evaluated using uniaxial compression testing, and the electrical energy stored within the matrix is quantified by calculating the area under the rate of capacitance curve. These findings support the development of an integrated, real-time sensing framework for predicting early-age concrete performance, with applications in quality control, precast concrete, cast-in-place construction, construction scheduling, and smart construction technologies.

Keywords

Viscosity, Capacitance, Rate of change of capacitance, Setting time, Green strength, Fluid-to-solid transition, Energy storage, Early-age changes in concrete, Electrochemical impedance spectroscopy, Cement hydration

Disciplines

Civil Engineering | Structural Materials

License

Creative Commons Attribution 4.0 International License
This work is licensed under a Creative Commons Attribution 4.0 International License.

Available for download on Saturday, August 28, 2027

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