Mo, Yi-Lung2018-11-262018-11-26August 2012013-08August 201http://hdl.handle.net/10657/3398Fiber research in concrete construction is an ongoing field and the use of carbon nanofibers (CNFs) will be examined in this study. Short-fiber composites are a class of strain sensor based on the concept of short electrically conducting fiber pull-out that accompanies slight and reversible crack opening. For a fiber composite to have strain sensing ability, the fibers must be more conducting than the matrix in which they are embedded, of diameter smaller than the crack length, and well dispersed. Their orientations can be random, and they do not have to touch one another. The electrical conductivity of the fibers enables the DC electrical resistivity of the composites to change in response to strain damage, hydration level, or temperature, allowing sensing. Because of the high cost associated with CNFs, a CNF aggregate (CNFA) was developed. The CNFA is a 16.39 cm3 (1.00 in.3) cubic specimen of CNF mortar. The CNF mortar is self-sensing and can be used to determine the hydration level, damage, or temperature in the multifunctional CNFAs. The CNFAs can be embedded in reinforced or prestressed concrete structures and used to monitor early strength, determine the localized damage, or measure the temperature in a structure.application/pdfengThe author of this work is the copyright owner. UH Libraries and the Texas Digital Library have their permission to store and provide access to this work. Further transmission, reproduction, or presentation of this work is prohibited except with permission of the author(s).Carbon nanofibersStructural health monitoringConcrete compositeSensors2018-11-26Thesisborn digital