Development of a Ridged Slip-Resistant Connection for Modular Aluminum Bridge Deck Applications
Loading...
Date
2018-12-04
Authors
St.Onge, James
Journal Title
Journal ISSN
Volume Title
Publisher
University of Waterloo
Abstract
Aluminum is a lightweight material that possesses excellent corrosion resistance and has been
shown to be an attractive alternative to steel and concrete for the construction and rehabilitation of
bridge structures. It is often possible to increase the load-carrying capacity of a bridge with an
existing concrete deck by reducing the structure’s self-weight through the installation of an
aluminum deck. For new construction, aluminum can allow for the use of accelerated bridge
construction (ABC) methods as the lightweight components can be easily transported and installed
on site. Aluminum also offers potential for lower life-cycle costs due to its high corrosion
resistance, which reduces maintenance requirements and eliminates the need for protective
coatings.
One of the latest developments in bridge construction and rehabilitation is the modular aluminum
bridge deck system, which consists of a series of pre-fabricated panels that are fastened together
to form a continuous deck. Welds and mechanical fasteners can both be used to join the panels
together. However, a mechanical fastening system is often advantageous for ease of transportation
and installation. Modular aluminum bridge deck systems offer all of the benefits that are associated
with the use of aluminum for bridge structures, and their modular design provides opportunities
for ABC methods in both new construction and rehabilitation projects. They are currently more
commonplace in Europe than in North America, however, which is due, in part, to a lack of
commercially available products in the North American market. There is a particular lack of
products that implement a mechanical fastening system for the panel-to-panel connections. A need
has therefore been identified to develop a novel modular aluminum bridge deck system with
mechanical connections for vehicular bridge structures in North America.
The research presented in this thesis focuses on the development of a novel ridged slip-resistant
connection for future implementation in a modular aluminum bridge deck system. Ridged slip-resistant
connections consist of interlocking faying surfaces, which are clamped together with
mechanical fasteners, with the goal of providing improved strength and ductility compared to
equivalent slip-resistant connections with flat faying surfaces. In the current study, their
performance is validated through experimental testing, finite element modelling, and the
development of a simple mechanistic model for predicting their slip-resistance.
An experimental program was carried out to study the performance of ridged and non-ridged slip-resistant
connections with carbon steel and stainless steel bolts. Static and cyclic tests were
performed on small-scale lap-splice specimens fabricated from 6061-T6 aluminum. The results of
the static tests were used to characterize the behaviour of ridged slip-resistant connections and to
quantify the performance gains between the ridged and non-ridged specimens. The results of the
cyclic tests were used to provide a preliminary assessment of the fatigue performance of ridged
slip-resistant connections.
Finite element (FE) modelling was conducted to predict the behaviour of each experimental test
specimen. The slip loads predicted by the FE models were compared to the experimental
observations and were then used in combination with the experimental observations to validate an
equilibrium-based mechanistic model. The mechanistic model was combined with the existing
design provisions of CSA S6 Canadian Highway Bridge Design Code (CSA Group, 2014) to
develop a design equation for aluminum ridged slip-resistant connections at the service limit state.
The stress concentrations predicted by the FE models were used as inputs for a strain-life analysis,
which was carried out to predict the fatigue lives of the cyclic experimental test specimens. Further
FE modelling was conducted to study a full-scale modular aluminum bridge deck system so that
the feasibility of implementing ridged slip-resistant connections between the panels could be
verified.
Description
Keywords
aluminum, aluminum bridges, modular aluminum bridge decks, slip-resistant connections