What we Hold Up

What we Hold Up

1. Materials

   • Material Properties
     • Physical Characteristics
       • Anisotropic
         • Different (wood)
       • Isotropic
         • Same (Gravel)
     • Modulus of Elasticity (MPa)
       • The amount of load it takes to deform the material one unit
     • Yield Strength (MPa)
       • The point at which the material will yield
   • Steel
     • Types of Steel Members
       • Beam
         • HSS
           • Channel
             • Angle
               • Plate
                 • Decking
                   • Most common: Corrugated Steel floor decking with a site-cast concrete topping
                   • Columns
                     • Perimeter Columns: Orient flange to wall
                     • Interior Columns: Orient web to wall
         • Flange: Resists Shear
         • Web: Resists Bending
     • Facts about Steel
       • Steel was at first used for fireproofing buildings
         • Steel is very efficient in tension
           • Steel loses strength when heated to 650 C, So it requires fireproofing
             • Steel becomes brittle (sudden failure) below -35 C
               • Steel has the highest strength and stiffness
               • Core-Ten Steel:
                 • Top layer corrodes and becomes an insulator and corrosion resistant
     • Steel Systems
       • Difficult to work on site
       • Built in a fabrication shop for easy construction
       • Connections
         • Most often bolted or welded
   • Concrete
     • Reinforced Concrete (Steel for tension)
       • Facts about Reinforced Concrete
         • Concrete is 10x better in compression than in tension
           • Good in compression, bad in tension
         • Good fireproofing
         • Possible admixtures (Fly ash)
       • Types of Concrete Systems
         • Flat Plate
           • Two way slab supported by columns (no beams) .
           • Light loads, short spans
           • Drop panels added to increase shear resistance
         • One way systems
           • Slabs mostly span in one direction, beam to beam or joist to joist
         • Two way systems
           • Slab spans two ways
     • Fiber Reinforced Concrete
       • High strength, very thin
       • Additives like Ductal, Fibre C, considered 'green' composite materials
   • Wood
     • Facts about wood
       • Wood is strong in tension, but limited by connections
         • Wood is mostly used in compression
       • Wood is weakest in compression perpendicular to the grain
     • Wood Systems
       • Hardwood
         • Softwood
       • Nominal vs Actual wood
         • Before and Dressed
       • Common Lumber Numbers
         • No 1 - 5 (Decreasing in quality)
       • Cell wall
         • Cellulose - Fibre Network
           • Lignin: Glue/Gel
             • Hemicellulose: Cross- Linking
     • Types of Wood
       • Engineered Wood Products
         • Sheet Products
           • Plywood
             • Laminations of veneer alternating directions
           • Medium Density Fibreboard
             • Not for structural applications
           • Oriented Strand Board
             • A cheaper, less stable in moisture sub for plywood
         • Spanning Members - Made of Dimensional Lumber
           • Cross Laminated Timber (CLT)
             • Each lamination switches directions
           • Glulam
         • Spanning Members - Made from Smaller Bits of Wood
           • Laminated Veneer Lumber (LVL)
             • All veneer laminations have grain in the same directions
           • Parallel Strand Lumber (PSL)
             • Strips of veneer at 12" by 12" or 18", then planed down
           • Laminated Strand Lumber (LSL)
             • Shredded wood from fast growing, low value hardwood
           • Structural Composite Lumber Products
         • Engineered Prefabricated Elements
           • I beams
             • Flange: LVL or solid sawn lumber Web: Plywood or OSB
           • I joists
           • Prefabricated Roof Trusses
             • Used by 4/5 homes in America
         • Distribute weaknesses
   • Plastic
     • Fiber Reinforced Plastics
       • Flexible, But brittle failure
   • Glass
     • Structural Glass
       • Brittle failure in tension
       • Structurally used for spanning with cables to provide tension
   • Masonry
     • Brittle, good in bearing
     • Reinforced with steel and grout/concrete for lateral stability
     • On facade: Not structural, but does reinforce in earthquakes

Images and files in the map