Date of Award

Spring 2012

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Civil/Environmental Engineering

Committee Director

Zia Razzaq

Committee Member

Ramamurthy Prabhakaran

Committee Member

Duc T. Nguyen

Committee Member

Ramappa Prabhakara

Committee Member

Mojtaba Sirjani

Abstract

The use of Near-Surface Mounted Carbon Fiber Reinforced Polymer (NSM-CFRP) reinforcement such as carbon FRP strips holds a high potential for increasing the flexural strength of reinforced concrete members. In comparison to externally bonded CFRP laminates, NSM-CFRP reinforcement approach has several advantages. The main advantages include increased stiffness and strength, better bonding, the possibility of anchoring the reinforcement into adjacent members, and minimal installation time. Thus, the structural engineers worldwide are developing a considerable interest in practical applications of the NSM-CFRP reinforcement technique. A considerable amount of research is still needed in order to fully benefit from this method not only for repairing and strengthening decaying infrastructure but also utilizing it for designing new infrastructure.

This research presents the outcome of a study of flexural response of reinforced concrete beams and slabs, with and without NSM-CFRP retrofitting, when subjected to static or impact loads. A total of twenty-three beams and four slabs were tested. The static behavior of the beams was predicted by coupling nonlinear moment-curvature relations with a finite-difference scheme and nonlinear moment area method. The performance of beams and slabs under impact load were evaluated using acceleration versus time relationships. A simplified single-degree-of-freedom elasto-plastic model was developed to capture their dynamic behavior.

New and intriguing retrofitting schemes developed in this research resulted in an increase in the strength of concrete members by 100% and stiffness by three-folds, several times higher than that achieved by past researchers. The structural members subjected to impact loading showed that such retrofitting scheme can dramatically reduce or practically eliminate punching shear and concrete shattering. Potential applications include those in concrete bridges, buildings, waterfront structures, dams, bunkers, as well as in earthquake- and blast-resistant structures.

DOI

10.25777/wkb7-v478

ISBN

9781267427359

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