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Activity:   Structural  Concepts’  (Part  Two)   Week  6     This  week  we  were   able  to  go  to  the   workshop  and  build  a   bridge  in  pairs.  We   tested  the  amount  of   force  that  could  be   applied  to  our   bridges  till  they   snapped.     Back  in  our  tutorial   room,  we  made  a   model  of  the  new   construction  area  of   Queens  College.    

                         

   

                                   

Akla  and  I  were  formed  group  four.  Our   materials  were:   -­‐ -­‐

1200  x  3.2  x  90  mm  Plywood  (x1)   1200  x  42  x  18  mm  Pinewood  (x3)  

We  cut  one  of  the  pine   wood  and  spit  it  into  8   smaller  blocks.    

We  did  not  need   perfect  measurements   because  the  purpose   was  not  to  make  the   best  bridge  in   aesthetics.        

After  nailing  the  first  few  blocks,  the   bridge  was  not  stable.  It  could  slide  from   side  to  side.  Only  after  we  a  nailed  all  the   blocks  into  the  two,  was  it  stable.      

Stud    -­‐  a  vertical  framing  member  used  to  create  walls  and   partitions.  Studs  can  be  either  wood  or  metal.     Beneke,  J.  2013.  Stud.  [online]  Available  at:   http://garages.about.com/od/glossary/g/StudGlossary.htm   [Accessed:  8  Sep  2013].  


We  focused  more  on  the  middle  of  the  bridge,   putting  more  support.  Having  4  beams  across   the  middle  and  another  2  on  the  sides.    

                     

       

Nails  of  different  head  shapes  and  sizes  were  used.  This  was   used  unintentionally.  But  Hamish  had  said  that  flat  heads  are   better  than  smaller  headed  nails.    This  is  because  the  smaller   ones  can  slip  right  through  the  two  pinewoods.      

           

Because  we  wanted  to  use  the  all  of   our  materials,  we  decided  to  place   attach  the  plywood  over  the  small   beams.  We  did  this  by  using  nails.    

  We  decided  on  making  this  face  of  the  bridge   the  bottom,  because  it  was  said  that  plywood   works  well  with  tension,  therefore  it’d  be  best   to  put  it  on  the  bottom  of  the  force  applied.    

       


Group  1:   -­‐ -­‐

 

Plywood  x2   Pinewood  x2  

                                  the  plywood  at  the   Before     was  snapped,  it  was   bottom     still  holding.   This  is  because     the  force  that  the  plywood  at     the  bottom   underwent  was         tension,  and  plywood  works   well  w   ith  tension  as  it  is  very     flexible.     The  p  art  that  was  snapped   was  w   here  the  nails  were  hit     aking  that  area  weaker.   into,  m            

Group  2:   -­‐ -­‐

Plywood  x2   Pinewood  x2   Group  two  had  a  similar   designed  bridge  as  group   one.  This  is  why  we  tested   the  bridge  from  another   side.        

The  maximum  applied   force  on  the  bridge  before   it  snapped,  was  350  kg.       Shear  force  plays  a  lot  in   the  snap  of  the  bridge.      

We  found  that  the  flatter   headed  nails  were  better,   because  they  do  not  go   straight  through  the   pinewood  like  the  smaller   nails  do.  

The  top  was  badly   crushed.    The  plywood   also  eventually   snapped  with  the   pinewood  that  was   under  all  the  force.    

 

 

The  bottom  pinewood   remained  unharmed  as   it  was  on  the  bottom,   but  the  plywood  kept   bending  away  from  the   bridge,  braking  away   from  the  nail.  


Group  3:  

 

-­‐ Plywood  x1     -­‐ Pinewood  x3     This  group’s  bridge  survived  the     most  amount  of  force  that  was     applied.  It  reached  up  to  380  kg  of     force.     The    screws  they  used  held  all     well  with  the  plywood.       ends                                   was  some  bending  coming   There     the  plywood  showcasing  tis   from     flexibility.       The    screws  worked  better  than  the     although  the  crack  was  found   nails,   at  the     area  where  the  nail  or  screw   was     put  in.            

Group  4:   -­‐ -­‐

 

Plywood  x1   Pinewood  x3   Our  group’s  bridge  survived   at  the  force  of  230  kg.    

  When  the  screws  were   screwed  in,  it   sometimes  split  the   timber  apart  because  it   did  not  follow  the   direction  of  the  grain,   making  it  weaker      

It  was  found  that  when   the  force  was  applied   to  the  bridge,  the   bridge  broke  at  the   nail.  This  is  because   once  the  nail  is   hammered  into  the   timber,  it  makes  it   weaker.        

The  plywood  was  put  at  the   bottom  because  it  was  said   that  it  works  well  with   tension  instead  of   compression.      


Queens  College  Model          

The  walls  are  made  from  concrete,   which  is  why  we  used  this   coloured,  cardboard.    By  reading  off   the  plans  of  Queens  College,  we   found  the  height  of  the  walls,   keeping  the  scales  the  same.  

Using  tracing  paper,  we  went  over   the  floor  plans  of  Queens  College  of   the  area  that  is  being  built.          

       

  The  courtyard  is   exposed  aggregate   concrete        

    Stairs        


Journal week 6