Part II: Material Selection

$(35$ marks$)$

Examine the various components of bridges listed below, choose suitable materials for each component, and analyse the properties $($e$.$g$.$ strength $($compresive$/$tensile$),$ ductility $,$ corrosion resistance, fatigue resistance, durability, versatility, and cost$-$effectiveness, weather resistance, aesthetic appeal, design flexibility, fire resistance, etc.$)$ of these materials. Discuss the life cycle of the selected materials and evaluate sustainability issues of those materials.

Superstructure:

Girders or Beams: Horizontal components supporting the deck and transferring loads to the substructure.

Deck: Surface on which vehicles, pedestrians, or trains travel.

Trusses: Assemblies of straight members connected at joints, used in some bridge designs to support the deck.

Arch: Used as superstructure elements, especially in masonry or stone bridges.

Suspension Cables: the main load$-$bearing members in suspension bridges.

Substructure:

Abutments: Supports at the ends of a bridge that resist the horizontal forces from the deck.

Piers: Vertical supports that bear the weight of the superstructure and transfer loads to the foundation.

Foundations $($piles$,$ caissons $)$: The base on which the bridge substructure rests, transferring loads to the ground.

Expansion Joints:

Expansion Joint Devices: Allow the bridge deck to expand and contract with temperature changes without causing damage.

Miscellaneous:

Bearings: Allow controlled movement between superstructure and substructure.

Railing$/$Parapets: Provides safety for vehicles and pedestrians.

Surface Protection:

Coatings: Applied to protect steel and concrete from corrosion.

Example:

$\backslash$table$[[$Material$,$Bridge component,Elements present $($composition$),\backslash$table$[[$Discuss the life cycle of selected$],[$materials and evaluate$],[$sustainability issues$]]],[$Masonry$,\backslash$table$[[$Arch$],[$Abutments$],[$Piers$]],\backslash$table$[[$Compressive Strength: Masonry$],[$materials excel in resisting compressive$],[$forces$,$ making them suitable for arches,$],[$abutments$,$ and piers in stone or brick$],[$bridges$.],[$Aesthetic Appeal: Stone and brick offer$],[$natural beauty and historical$],[$significance$,$ enhancing the visual appeal$],[$of bridges in certain contexts.$],[$Weather Resistance: Well$-$built masonry$],[$structures can withstand weathering$],[$and environmental exposure,$],[$contributing to their longevity.$]],\backslash$table$[[$Extraction $$ Manufacturing $$

Question $3$:

$(35$ marks$)$

Discuss based on the following materials: $(1).$ Reinforced concrete, $(2).$ Steel, $(3).$ Timber, $(4).$ Brick, $(5).$ Rubber$/$Polymers $($Epoxy$,$ polyurethane etc.$),(6).$ Rock$/$stone$,(7).$ Another material different from the above.

$(5$ marks for each material$)$