possible the cost-effective construction of high-quality bridges over a wide
range of conditions and span lengths including highway alignment. Bridge
structures constructed using post-tensioning have high intrinsic durability and
are able to be built quickly with minimal impact on the human and natural
environment. Further, structures constructed using post-tensioning also benefit
from the method's ability to limit cracking, reduced structural depth, ease of
accommodating curved roadway alignment and low maintenance costs. And, these
benefits do not come at the expense of aesthetic expression.
construction has become the preferred method of building long-span concrete
bridges as well as concrete arches with the help of temporary towers and stays.
It is a proven cost-effective means of building spans ranging from 200-feet (60
m) to more than 1,000-feet (300 m). It has been used to cross major bodies of
water, deep mountain canyons, and densely populated urban areas. Further, post-tensioning
can be used effectively to build bridges on alignments that are curved in plan.
which can be built quickly and without touching the land or water below the
bridge, are a relatively low impact structural system and optimal solution. For
longer spans (commonly up to 300-feet or more), shallower girder depths, and
continuously curved superstructures, post-tensioning offers ductility and
seismic performance as well as superior aesthetics to today's precast designs. Post-tensioning
also provides more flexibility in the layout of span lengths, bent
configurations and roadway geometrics than precast I-girders or reinforced
concrete box girders.
Advantages of precast segmental bridge construction include:
- The economy of
precast prestressed concrete construction is extended to a span range of 100 to
400 feet (30 to 120 m). Longer spans may be economical where use of heavy
erection equipment is feasible.
segments may be fabricated while the substructure is being built, and rapid
erection of the superstructure can be achieved.
control because of the repetitive industrialized manufacturing techniques, with
the inherent potential of achieving high-performance concrete.
interference with Bridge Environment: The need for false work is eliminated and
all erection may be accomplished from the top of the completed portions of the
bridge. This may be of particular importance for high-level crossings or in
cases where it is necessary to minimize interference with the bridge
The effects of
creep and shrinkage are substantially minimized through the use of precast
segments that have matured to full strength.
Publications and Certification Relating to PT Bridge Construction: