Heather Parry

Date of Award

8-2013

Level of Access Assigned by Author

Campus-Only Thesis

Degree Name

Master of Science (MS)

Department

Civil Engineering

Advisor

Roberto A. Lopez-Anido

Second Committee Member

William Davids

Third Committee Member

Habib Dagher

Abstract

Research is currently underway to create a feasible solution for splicing concrete-filled fiber-reinforced polymer (FRP) tubes (CFFTs). This technology is used in bridge construction where tubular FRP arches are placed parallel to the roadway, and filled with a self-consolidating concrete (SCC) mix on site. The tubes have an FRP deck fastened on the top side, a granular backfill, and a bituminous pavement. The FRP tubes act as exo-skeletal reinforcement for the concrete. The advantages over typical steel or concrete bridges can include speed of construction, low maintenance costs, and cost reduction for the appropriate site conditions. AASHTO specifications for these arches were approved in the summer of 2012. One current limitation of the technology is the ability to ship longer arches. A splice design is described in this thesis, which facilitates use of long-span arches.

A splicing solution using a combination of internal rebar reinforcing and an outer FRP collar to connect the two sides of the arch is considered. The internal solution is being evaluated using three different types of reinforcement: 1) Steel rebar (baseline material); 2) E-glass fiber reinforced rebar; and 3) Carbon fiber composite cable (CFCC). The goal is to develop an all FRP composite bridge solution. The internal reinforcing will carry all of the loads during the bridge service life. The external reinforcing for the splice will consist of an FRP composite collar attached with mechanical fasteners and will sustain the loads due to erection, concrete filling of the tubes, and associated construction live loads. The mechanically fastened splice eliminates the need for surface preparation and adhesive bonding in the field, speeding construction and enabling efficient quality control of the installation process.

This thesis investigates a splice design that will be used for implementation in construction of longer span arch bridges. The tested splice design incorporates a steel rebar cage for internal reinforcing and a mechanically fastened external reinforcing collar. The experimental work included: collar fastener bearing strength, internal rebar pullout strength, and hollow CFFT beam spliced with the external reinforcing collar. The full scale splice with internal and external reinforcing was experimentally validated in CFFT beam tests. From the experimental results it can be concluded that the splice is structurally adequate, but is conservative. Further testing and analysis should be conducted to improve on the proposed splice design.

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