Appeal 2007-2596
Application 10/370,634
BACKGROUND
“Post-tensioning of concrete structures has been known in the art for
many years. In post-tensioning, tendons are placed through a concrete
structure and then tensioned using hydraulic jacks in order to place the
concrete structure under compression” (Specification 1). A pervasive
problem with post-tensioned structures “is corrosion of the tendons, which
results in degradation in the strength of the structure. In general, a filler
material such as grout or grease has been used in the prior art in order to
attempt to protect the tendons against corrosion” (id.).
The Specification discloses a post-tensioning method that uses “a
tubular structure configured and dimensioned to provide a continuous void
through a concrete structure, first and second anchor members disposed at
opposite ends of the tubular structure, and at least one stainless steel strand
extending through the tubular structure and secured under tension between
the anchor members” (id. at 2). The Specification discloses that “[t]he
anchor members are mounted to close and maintain the void with the void
being unfilled such that the strand may be easily removed and replaced for
inspection and maintenance” (id.). Using stainless steel strands “reduces or
eliminates corrosion such that the use of grout, grease or other filler
materials are not required for protection of the cables” (id. at 3).
DISCUSSION
1. CLAIMS
Claims 1-7 and 13-23 are on appeal. Claims 1 and 13 are
representative and read as follows:
1. A post-tensioning system for concrete structures,
comprising:
2
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Last modified: September 9, 2013