Date of Award

11-2015

Document Type

Thesis

Degree Name

Master of Science in Civil Engineering (MSCE)

Department

Civil Engineering

First Advisor

Dr. Tamer El Maaddawy

Second Advisor

Dr. Najif Ismail

Third Advisor

Dr. Kamal H. Khayat

Abstract

The effectiveness of using carbon textile-reinforced mortar as an innovative technique to improve the shear response of reinforced concrete beams has been investigated. The research comprised double-shear bond testing on bond behavior of textile-reinforced mortar, large-scale beam testing on shear response of reinforced concrete beams strengthened with textile-reinforced mortar, and nonlinear finite element modeling of the tested beam specimens. Test variables of the double-shear bond testing were the matrix type, and width/length of the bonded area, whereas for the large-scale beam testing, the variables included the number of textile-reinforced mortar layers, matrix type, and amount of internal stirrups. Results of the double-shear bond tests demonstrated that delamination of the textile fabric governed the failure of the specimens without debonding at the concrete/matrix interface. The bond stress of the specimens with a cementitious mortar-based matrix was on average 28% lower than that of their counterparts with an epoxy-based matrix. For the same bonded area, the bond stress tended to decrease with an increase in the bonded length of the fabric. Results of the large-scale beam testing demonstrated that the shear strength gain caused by strengthening was in the range of 51% to 145% depending on the amount of internal stirrups and number of textile-reinforced mortar layers. The shear strength gain decreased with an increase in the amount of internal stirrups. Increasing the number of textile-reinforced mortar layers increased the shear capacity but the additional shear strength gain was not proportional to the added amount of layers. The use of epoxy adhesive rather than a cementitious mortar as a matrix slightly increased the shear strength gain. The effect of increasing the amount of textile- viii reinforced mortar and varying the matrix type was less pronounced for the specimens with internal stirrups. The finite element models developed in this study were able to predict the nonlinear shear response of the tested specimens. A comparison between the predicted and experimental results confirmed the accuracy and validity of the developed finite element models.

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