Semester

Spring

Date of Graduation

2016

Document Type

Problem/Project Report

Degree Type

MS

College

Statler College of Engineering and Mineral Resources

Department

Civil and Environmental Engineering

Committee Chair

Hota V.S. GangaRao

Committee Co-Chair

Ruifeng Liang

Committee Member

Mark L. Skidmore

Abstract

Many ageing highway bridges are in distress, requiring urgent repairs or rehabilitation. About 10% of the total highway bridges require rehabilitation in United States of America (Houlihan, April 2015). Reconstruction of these bridges requires large sums of money and time consuming conventional rehab schemes. Herein, a novel rehab scheme with Fiber Reinforced Polymer (FRP) composites has been evaluated in the laboratory as FRPs exhibit high strength to weight ratio, high stiffness and excellent corrosion resistance. Current methods to repair pile systems are limited by access issues as the piles are extended typically underwater and below the mudline. Traditional methods require cofferdams or other barrier systems to work in the dry or divers to work in the wet. Access is also hindered as the piles support the existing bridge; i.e. there is a structure overhead and repairs have to be made around the existing pile supporting super structure. Proper repairs typically require digging below the mudline, which complicates any traditional repair method. The repair method proposed herein seeks to solve both the access and excavation issues by combining an augering attachment to FRP formwork that can be installed around an existing pile. Twisting the FRP formwork engages the auger, which drives the forms below the mudline. This method can be adopted above water, eliminating the need for barrier systems or divers. The auger attachment can be modified based on soil conditions. As the shell bores down, additional shells can be attached to the previously attached shell by an overlapping joint and also reinforcing the shell with FRP composite wrap to prevent potential buckling under torsion and to minimize moisture ingress through the shell. Based on the compactness of the soil and/or hardness, FRP composites can be selected with proper fiber volume fraction and orientation. In this study, field conditions have been replicated in lab and three different kinds of Auger attachments to the FRP composite shell are tested with manual application of torque to understand various challenges in driving these shells below the mudline. The stresses developed in the shell, both by the application of torque and resistance offered by soil are measured using of strain gages. The strain gage readings are evaluated with respect to strain limits of FRP composite to understand the FRP-soil interaction and to attain safe shell design. Plastic waste is the other major issue at present. The production is increasing every year rapidly but the recycling is not. The plastic waste that is not recycled is dumped in oceans or landfilled causing disturbance in ecological cycle. To reduce ecological disturbance, a compounding machine converting the plastic waste into a structurally useful product has been discussed herein as a second part of this report.

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