Common
approaches include either one
or more of the following:
¶
Reduction
of dead load: By removing an existing heavier deck &
replacing it by lightweight decks such as :
- Open-Grid
steel decks
- Exodermic
deck
- Laminated
timber deck
- Lightweight
concrete deck
- Aluminium/steel
orthotropic steel deck
¶
Introducing
composite action: Modification of an existing stringer
& deck system to a
composite system is a common method for increasing the flexural
strength of
bridge.
¶
Improving
the strength of various bridge members: The common
measures include:
- Addition
of Steel Cover Plates
- External
shear reinforcement for concrete, steel & timber beams
- Adding
Lateral Supports or Stiffeners
- Epoxy
Injection
- Rebar
Injection
- Jacketing
of timber/concrete Piles & Pier columns
- Post-Tensioning
various bridge components
¶ Developing
additional bridge continuity: The common measures include:
- Addition
of supplemental supports
- Modification
of simple spans : Simply Supported adjacent spans are connected
together with a
moment & shear-type connection
¶ Recent
developments:
- Epoxy
bonded steel plates
- CFRP
Plate strengthening
Note:
We have confined ourselves to general measures to be adopted for Super
Structure & not discussed specialized problems of other components
(like expansion joints & bearings)
