Project Title:
PIs:
Institution:
Cost:
Advancing Accelerate Bridge Construction (ABC) Concepts
John Mander and Mary Beth Hueste
Texas A&M University
$100,000
Background Statement
Bridges nowadays are normally constructed using a mix of cast-in-place (CIP) and precast [or prefabricated]
construction techniques. If one examines the construction schedule, much of the site occupation time is consumed
with the CIP construction activities, specifically, formwork and falsework placement, reinforcing steel placement,
and pouring concrete. Accelerated bridge construction (ABC) offers alternative design solutions that can minimize
site possession, thereby saving project time and cost, specifically minimize significant delay times, speed
restrictions, and detours due to lengthy construction schedules at bridge sites. Moreover, the time-cost-of-money
can be further minimized if the construction period is shortened. The use of precast, prestressed concrete (PSC)
structural elements provides another advantage in terms of durability due to the use of plant controlled conditions for
fabrication and the ability to design for uncracked sections under service loads. Therefore, the use of PSC elements
in advanced ABC methods provides an ideal combination for minimizing disruption to the public during both the
bridge construction stage and over the longer service life of the structure.
Objectives & Work Description
Most ABC solutions to date use some site casting of concrete. Specifically these are classified as “wet” connections.
More specifically for example, precast decks have a reinforced concrete (RC) topping; hollow precast pier segments
are reinforced and infilled with site-cast concrete. The technical objective of this research is to advance ABC by
minimizing the amount of concrete cast on site—in fact where possible to eliminate CIP-RC and replace concreting
with limited volumes of grouting. To achieve this, piers can be fully precast with “dry-joints” and post-tensioned,
while decks can be full-depth RC/PSC with a thin [unreinforced] wearing course topping.
The proposed work scope consists of developing several ABC approaches, with trial designs, where all
bridge components are precast and the units connected by either dry or wet concrete connections. Comparative
standard designs would also be made. In particular, the project would develop a complete precast concrete
substructure system for bridges with short to medium spans up to say 200-ft. The pier bent columns would be dryjointed and connected to the pile and pier caps via post-tensioned prestress. A deck system will also be developed
that does not require rebar placement, but uses wet joints to connect panels and provide the final riding surface.
Construction schedules and cost estimates of the various ABC and CIP designs would then be compared.
Promising ABC design solutions would then serve as a basis for future testing of components and subassemblies
prior to developing a demonstration project that would be proposed for implementation within one of the states that
host the UTC.
Why is your team best for this project?
This team is best for the project for the following reasons:
1. Prof. Mander has over 30 years of experience in bridge design, analysis and structural testing.
2. Prof. Hueste has significant experience in the design, analysis and laboratory testing of reinforced and
prestressed concrete bridge members, including several projects with TxDOT.
3. Prof. Mander was instrumental in initiating and conceiving a form of rapid construction in a seismic design
context called “Damage Avoidance Design.” This work was initially funded by FHWA in the 1990s and
solutions for bridge piers were developed. Subsequently, Mander and his co-workers have expanded the
concepts into building systems, particularly long-span building systems that are often now used for parking
garages.
4. Prof. Mander plus other co-workers at TTI successfully tested and developed a new type of precast concrete
deck system, with a particular emphasis on dealing with the overhang problem aimed at completely removing
the shoring—this solution has already been implemented in a bridge in Fort Worth. The proposed work intends
to extend this considerably further by removing the field placement of reinforcing steel.
5. Profs. Hueste and Mander presently are engaged in two somewhat related research projects with TxDOT that
are dealing with splicing technology developments for prestressed girder bridges (TxDOT 0-6651), and a new
type of modular precast slab-beam bridge system (TxDOT 0-6722). The intent is to capitalize upon and
leverage this knowledge and these current efforts to enhance the outcomes of the present proposed research.