Semester

Summer

Date of Graduation

2014

Document Type

Thesis

Degree Type

MS

College

Statler College of Engineering and Mineral Resources

Department

Civil and Environmental Engineering

Committee Chair

P. V. Vijay

Committee Co-Chair

Hota V. GangaRao

Committee Member

Udaya B. Halabe

Committee Member

P. V. Vijay.

Abstract

Concrete and steel have been predominantly used in civil and hydraulic infrastructure construction. With several years of service under adverse climatic conditions, those structures have exhibited moderate to severe deterioration and composite materials are emerging as one of the most feasible and economical materials for their rehabilitation. This report describes and highlights the research work conducted on: i) rehabilitation of underwater concrete structures with FRP, and ii) evaluation of abrasion resistant coatings for hydraulic steel gates.;Curing of certain class of resins under water has unfolded the possibility of utilizing fiber reinforced polymers (FRPs) to repair submerged piles and pier structures. In this study, GFRP pre-preg with water curable urethane resin was used to wrap concrete cylinders. Laboratory testing shows the increase in strength, stiffness, and ductility of concrete cylinders with underwater FRP wrapping. Lab evaluation also indicates that underwater FRP system is effective in dry surface wrapping (ambient field conditions) as well. Threefold increase in load capacity (1921 psi vs. 6865 psi) and 3.22 times increment in energy absorption was observed with 5 layers of wrapping. Concrete cylinders with steel sections and wrapped with 2 layers of Aquawrap also showed significant increase in load capacity with more than 92% degree of compositeness. By applying basic confinement effect equations, theoretical strengths were in good correlation with experimental values. Following lab work, the rehabilitation work was conducted on submerged concrete discharge ports of Chickamauga lock and dam, and steel piles of East Lynn Lake Bridge.;This research also focuses on the study of abrasion characteristics and comparative abrasion tests on different abrasion resistant coating systems. Conditions of severe abrasion exist at some high-lift dams that cause standard protective coatings on the downstream side of tainter gates to be abraded away in just few years of service. Down-stream side of protective coating system is damaged typically by debris that swirls and bangs against the gate causing severe cutting and abrasion to the coatings. This study was aimed at identifying composite based coating that can withstand hydraulic forces from high velocity water and also minimize the effects of severe cutting, impact, and abrasive forces generated from barge and sand particles on tainter gates at Heflin Lock & Dam near Gainesville, Alabama. In this research, six different types of abrasion resistant coating materials/systems were applied on sand blasted metallic plates in order to perform comparative abrasion tests using TABER reciprocating abrader. Among six different coating systems, ceramic composite based coatings provided better performance (up to twice or better) over the conventional coatings.

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