File:Tweedriver.png

2013-04-27T23:03:46Z

Kinglamkwan:

Kinglamkwan:

Recycled plastic bridges

2013-04-26T02:17:33Z

Kinglamkwan:

1. INTRODUCTION

2. PROBLEMS WITH EXISTING BRIDGES

2.1 CONCRETE BRIDGES

2.2 MASONRY BRIDGES

3. ADVANTAGES AND DISADVANTAGES OF RECYCLED PLASTIC BRIDGES

3.1 ADVANTAGES

3.2 DISADVANTAGES

4. MECHANICAL PROPERTIES OF RECYCLED PLASTICS

5. EXAMPLES OF PLASTIC BRIDGES

6. EXTERNAL REFERENCES

----

'''1. INTRODUCTION''' Bridges are considered as an important connection between places. They are as much part of the Roman architectural achievement as aqueducts. (1) From prehistoric times, to modern ages, people or engineers construct various types of bridges using concrete, masonry, iron etc. Up till now, engineers started to consider the possibility of using recycled plastic instead of traditional materials to construct bridges. Other than the advantages of using plastic over traditional materials as construction material, this can also save a huge amount of plastic. The UK uses over 5 million tonnes of plastic each year of which an estimated 24% is currently being recovered or recycled. (2) A further portion can then be recycled and used for constructing bridges. This is a huge breakthrough and perhaps a new era of bridges.

----

'''2. PROBLEMS WITH EXISTING BRIDGES'''

'''2.1 CONCRETE BRIDGES'''

Concrete has a relatively high compressive strength and can be reinforced with materials strong in tension such as steel. However, using concrete as a construction material may cause problems. The structure may be attacked and thereby the stability of it may decrease. For example, problems like chloride penetration, carbonation, alkali silica reactions, structural cracks, damage due to accidents and explosions may occur, reducing the strength of concrete. Most of this damage with bridges will be in the wearing course and/or deck construction and the repair or maintenance may not last long. (3)

'''2.2 MASONRY BRIDGES'''

Masonry arch bridges fail mainly due to scouring. The foundations of a masonry arch bridge are generally shallow and therefore susceptible to scour. (4) For example, severe rainfall in Southern Ireland in August 1986 resulted in considerable flood damage to bridges; nine bridges were badly damaged or demolished in County Wicklow alone. (5) Also, when cracks appear in the arches, rainwater may enter the cracks, further enlarging them which may then causes the arch to collapse.

----

'''3. ADVANTAGES AND DISADVANTAGES OF RECYCLED PLASTIC BRIDGES'''

'''3.1 ADVANTAGES'''

The advantages are concerned with environmental aspects:
*They do not need regular maintenance
*Most of the plastic used are chemically inert, prolonging its lifespan
*They are stable even in saltwater
*Once the bridge has completed its lifespan, the plastic can be recycled again and not being dumped into landfills (6)
*They are resistant to rot and damage from insects (7), which is an advantage when compared to timber

'''3.2 DISADVANTAGES'''

The disadvantages are concerned with economic aspects:
*The construction cost is relatively higher than the bridges built with traditional materials
*The payback period of the bridge is long

----

'''4. MECHANICAL PROPERTIES OF RECYCLED PLASTICS''' Since there are not many pioneers in constructing plastic bridges, the utilisation of such recycled materials may not be as effective as expected. Research can be made into making I-beams with plastics in a more effective way which helps save materials used. This may reduce the cost needed to construct plastic bridges, providing incentives to the construction industry. Moreover, recycled plastics are ground and moulded in different recycling process for several times. This may cause the glass fibre chain length to decrease, and mechanical properties such as ultimate tensile strength may decrease as a result. (8) Therefore, more research can be carried out to maximise the mechanical properties of the mixed recycled plastics. By that time, plastic bridges can be constructed in a larger scale.

----

'''5. EXAMPLES OF PLASTIC BRIDGES'''

5.1 Bridge across the Tweed River, Scotland, UK

A Welsh startup called Vertech has built a bridge across the Tweed River. Measuring 30 metres in length and made entirely out of waste plastic products, the newly completed structure is the world's longest and sturdiest recycled bridge. (6) This bridge is entirely made up of recycled plastic. The installation process was relatively simple. It was designed by engineers from Rutgers and Cardiff Universities, then constructed off-site and brought into place, where it was then assembled in four days. The entire process of putting the bridge together took less than two weeks. (9)

5.2 Bridge at Fort Bragg, North Carolina, USA

Axion International Holdings, Inc. has built a bridge made of recycled plastic at Fort Bragg, in North Carolina. The bridge consists of 94 percent recycled materials including glass, vehicle bumpers and about 85,000 pounds of high-density polyethylene plastic. (10) The Army predicts the bridge, which is expected to last half a century, will bring a 34 to 1 return on investment by using the technology in certain bridge applications. (11) The bridge is so strong that it can carry the weight of a tank of 68.7 tons on it.

5.3 Footbridge at Santa Rosa Valley, California, USA

The pedestrian bridge is 25 feet long and 10 feet across. It was constructed across the Arroyo Santa Rosa to help connect a portion of a trail that was washed out during heavy rains. (12) This bridge is made of recycled plastic, and is particularly useful in the area because of saltwater concentrations in the environment - steel rusts, concrete cracks and wood rots. (13)

----

'''6. EXTERNAL REFERENCES'''
#History World ''HISTORY OF BRIDGES'' [http://www.historyworld.net/wrldhis/plaintexthistories.asp?historyid=ab97 http://www.historyworld.net/wrldhis/plaintexthistories.asp?historyid=ab97]
#British Plastics Federation ''Plastics Recycling [http://www.bpf.co.uk/sustainability/plastics_recycling.aspx http://www.bpf.co.uk/sustainability/plastics_recycling.aspx]''
#CONTEC Aps ''Concrete Bridges and Viaducts'' [http://www.contec-aps.com/business-areas/bridges-rehabilitation/concrete-bridges-and-viaducts.html http://www.contec-aps.com/business-areas/bridges-rehabilitation/concrete-bridges-and-viaducts.html]
#Universidade do Minho ''STRENGTHENING OF STONE MASONRY ARCH BRIDGES'' [http://www.ce.tuiasi.ro/~ccf/lucrari_disertatie/ApreuteseiVlad.pdf http://www.ce.tuiasi.ro/~ccf/lucrari_disertatie/ApreuteseiVlad.pdf]
#J Page (1993) ''Masonry Arch Bridges''. HMSO
#CNN ''World's longest recycled bridge spans Scottish river'' [http://edition.cnn.com/2011/12/06/world/recyclable-bridge http://edition.cnn.com/2011/12/06/world/recyclable-bridge]
#WORLDNETDAILY ''THE ARMY'S FIRST PLASTIC BRIDGE'' [http://www.wnd.com/2009/09/110770/ http://www.wnd.com/2009/09/110770/]
#Harold Cornier-Rios (2003) ''EFFECT OF RECYCLING ON MATERIAL PROPERTIES OF POLYETHYLENE TEREPHTHALATE AT VARIOUS RECYCLING RATIOS AND RECYCLING GENERATIONS''. University of Puerto Rico [http://www.me.uprm.edu/News/Tesis%20Harold.pdf http://www.me.uprm.edu/News/Tesis%20Harold.pdf]
#Duncan Geere (2011) ''Recycled plastic bridge spans Welsh river'' [http://www.wired.co.uk/news/archive/2011-10/26/recycled-plastic-bridge http://www.wired.co.uk/news/archive/2011-10/26/recycled-plastic-bridge]
#USAEC (2009) ''FORT BRAGG TESTS RECYCLED PLASTIC BRIDGE'' [http://aec.army.mil/usaec/newsroom/update/fall09/fall0904.html http://aec.army.mil/usaec/newsroom/update/fall09/fall0904.html]
#WORLDNETDAILY ''THE ARMY'S FIRST PLASTIC BRIDGE'' [http://www.wnd.com/2009/09/110770/ http://www.wnd.com/2009/09/110770/]
#Michele Willer-Allred (2011) ''Arroyo Santa Rosa's plastic bridge project moves ahead''. Scripps Interactive Newspapers Group [http://www.vcstar.com/news/2011/dec/23/arroyo-santa-rosas-plastic-bridge-project-moves/ http://www.vcstar.com/news/2011/dec/23/arroyo-santa-rosas-plastic-bridge-project-moves/]
#Michele Willer-Allred (2012) ''Pioneering plastic bridge opens in Santa Rosa Valley''. Scripps Interactive Newspapers Group [http://www.vcstar.com/news/2012/dec/07/plastic-bridge-in-santa-rosa-valley-opens-to/ http://www.vcstar.com/news/2012/dec/07/plastic-bridge-in-santa-rosa-valley-opens-to/]

[[Category:CIOB_competition]]
[[Category:Products_/_components]]
[[Category:Sustainability]]

Recycled plastic bridges

2013-04-26T02:17:03Z

Kinglamkwan: Created page with " '''RECYCLED PLASTIC BRIDGES''' 1. INTRODUCTION 2. PROBLEMS WITH EXISTING BRIDGES 2.1 CONCRETE BRIDGES 2.2 MASONRY BRIDGES 3. ADVANTAGES AND DISADVANTAGES OF RECYCLED..."

'''RECYCLED PLASTIC BRIDGES'''

1. INTRODUCTION

2. PROBLEMS WITH EXISTING BRIDGES

2.1 CONCRETE BRIDGES

2.2 MASONRY BRIDGES

3. ADVANTAGES AND DISADVANTAGES OF RECYCLED PLASTIC BRIDGES

3.1 ADVANTAGES

3.2 DISADVANTAGES

4. MECHANICAL PROPERTIES OF RECYCLED PLASTICS

5. EXAMPLES OF PLASTIC BRIDGES

6. EXTERNAL REFERENCES

----

'''1. INTRODUCTION'''
Bridges are considered as an important connection between places. They are as much part of the Roman architectural achievement as aqueducts. (1) From prehistoric times, to modern ages, people or engineers construct various types of bridges using concrete, masonry, iron etc. Up till now, engineers started to consider the possibility of using recycled plastic instead of traditional materials to construct bridges. Other than the advantages of using plastic over traditional materials as construction material, this can also save a huge amount of plastic. The UK uses over 5 million tonnes of plastic each year of which an estimated 24% is currently being recovered or recycled. (2) A further portion can then be recycled and used for constructing bridges. This is a huge breakthrough and perhaps a new era of bridges.

----

'''2. PROBLEMS WITH EXISTING BRIDGES'''

'''2.1 CONCRETE BRIDGES'''

Concrete has a relatively high compressive strength and can be reinforced with materials strong in tension such as steel. However, using concrete as a construction material may cause problems. The structure may be attacked and thereby the stability of it may decrease. For example, problems like chloride penetration, carbonation, alkali silica reactions, structural cracks, damage due to accidents and explosions may occur, reducing the strength of concrete. Most of this damage with bridges will be in the wearing course and/or deck construction and the repair or maintenance may not last long. (3)

'''2.2 MASONRY BRIDGES'''

Masonry arch bridges fail mainly due to scouring. The foundations of a masonry arch bridge are generally shallow and therefore susceptible to scour. (4) For example, severe rainfall in Southern Ireland in August 1986 resulted in considerable flood damage to bridges; nine bridges were badly damaged or demolished in County Wicklow alone. (5) Also, when cracks appear in the arches, rainwater may enter the cracks, further enlarging them which may then causes the arch to collapse.

----

'''3. ADVANTAGES AND DISADVANTAGES OF RECYCLED PLASTIC BRIDGES'''

''' 3.1 ADVANTAGES'''

The advantages are concerned with environmental aspects:
*They do not need regular maintenance
*Most of the plastic used are chemically inert, prolonging its lifespan
*They are stable even in saltwater
*Once the bridge has completed its lifespan, the plastic can be recycled again and not being dumped into landfills (6)
*They are resistant to rot and damage from insects (7), which is an advantage when compared to timber

''' 3.2 DISADVANTAGES'''

The disadvantages are concerned with economic aspects:
*The construction cost is relatively higher than the bridges built with traditional materials
*The payback period of the bridge is long

----

'''4. MECHANICAL PROPERTIES OF RECYCLED PLASTICS'''
Since there are not many pioneers in constructing plastic bridges, the utilisation of such recycled materials may not be as effective as expected. Research can be made into making I-beams with plastics in a more effective way which helps save materials used. This may reduce the cost needed to construct plastic bridges, providing incentives to the construction industry. Moreover, recycled plastics are ground and moulded in different recycling process for several times. This may cause the glass fibre chain length to decrease, and mechanical properties such as ultimate tensile strength may decrease as a result. (8) Therefore, more research can be carried out to maximise the mechanical properties of the mixed recycled plastics. By that time, plastic bridges can be constructed in a larger scale.

----

'''5. EXAMPLES OF PLASTIC BRIDGES'''

5.1 Bridge across the Tweed River, Scotland, UK

A Welsh startup called Vertech has built a bridge across the Tweed River. Measuring 30 metres in length and made entirely out of waste plastic products, the newly completed structure is the world's longest and sturdiest recycled bridge. (6) This bridge is entirely made up of recycled plastic. The installation process was relatively simple. It was designed by engineers from Rutgers and Cardiff Universities, then constructed off-site and brought into place, where it was then assembled in four days. The entire process of putting the bridge together took less than two weeks. (9)

5.2 Bridge at Fort Bragg, North Carolina, USA

Axion International Holdings, Inc. has built a bridge made of recycled plastic at Fort Bragg, in North Carolina. The bridge consists of 94 percent recycled materials including glass, vehicle bumpers and about 85,000 pounds of high-density polyethylene plastic. (10) The Army predicts the bridge, which is expected to last half a century, will bring a 34 to 1 return on investment by using the technology in certain bridge applications. (11) The bridge is so strong that it can carry the weight of a tank of 68.7 tons on it.

5.3 Footbridge at Santa Rosa Valley, California, USA

The pedestrian bridge is 25 feet long and 10 feet across. It was constructed across the Arroyo Santa Rosa to help connect a portion of a trail that was washed out during heavy rains. (12) This bridge is made of recycled plastic, and is particularly useful in the area because of saltwater concentrations in the environment - steel rusts, concrete cracks and wood rots. (13)

----

'''6. EXTERNAL REFERENCES'''
#History World ''HISTORY OF BRIDGES'' [http://www.historyworld.net/wrldhis/plaintexthistories.asp?historyid=ab97 http://www.historyworld.net/wrldhis/plaintexthistories.asp?historyid=ab97]
#British Plastics Federation ''Plastics Recycling [http://www.bpf.co.uk/sustainability/plastics_recycling.aspx http://www.bpf.co.uk/sustainability/plastics_recycling.aspx]''
#CONTEC Aps ''Concrete Bridges and Viaducts'' [http://www.contec-aps.com/business-areas/bridges-rehabilitation/concrete-bridges-and-viaducts.html http://www.contec-aps.com/business-areas/bridges-rehabilitation/concrete-bridges-and-viaducts.html]
#Universidade do Minho ''STRENGTHENING OF STONE MASONRY ARCH BRIDGES'' [http://www.ce.tuiasi.ro/~ccf/lucrari_disertatie/ApreuteseiVlad.pdf http://www.ce.tuiasi.ro/~ccf/lucrari_disertatie/ApreuteseiVlad.pdf]
#J Page (1993) ''Masonry Arch Bridges''. HMSO
#CNN ''World's longest recycled bridge spans Scottish river'' [http://edition.cnn.com/2011/12/06/world/recyclable-bridge http://edition.cnn.com/2011/12/06/world/recyclable-bridge]
#WORLDNETDAILY ''THE ARMY'S FIRST PLASTIC BRIDGE'' [http://www.wnd.com/2009/09/110770/ http://www.wnd.com/2009/09/110770/]
#Harold Cornier-Rios (2003) ''EFFECT OF RECYCLING ON MATERIAL PROPERTIES OF POLYETHYLENE TEREPHTHALATE AT VARIOUS RECYCLING RATIOS AND RECYCLING GENERATIONS''. University of Puerto Rico [http://www.me.uprm.edu/News/Tesis%20Harold.pdf http://www.me.uprm.edu/News/Tesis%20Harold.pdf]
#Duncan Geere (2011) ''Recycled plastic bridge spans Welsh river'' [http://www.wired.co.uk/news/archive/2011-10/26/recycled-plastic-bridge http://www.wired.co.uk/news/archive/2011-10/26/recycled-plastic-bridge]
#USAEC (2009) ''FORT BRAGG TESTS RECYCLED PLASTIC BRIDGE'' [http://aec.army.mil/usaec/newsroom/update/fall09/fall0904.html http://aec.army.mil/usaec/newsroom/update/fall09/fall0904.html]
#WORLDNETDAILY ''THE ARMY'S FIRST PLASTIC BRIDGE'' [http://www.wnd.com/2009/09/110770/ http://www.wnd.com/2009/09/110770/]
#Michele Willer-Allred (2011) ''Arroyo Santa Rosa's plastic bridge project moves ahead''. Scripps Interactive Newspapers Group [http://www.vcstar.com/news/2011/dec/23/arroyo-santa-rosas-plastic-bridge-project-moves/ http://www.vcstar.com/news/2011/dec/23/arroyo-santa-rosas-plastic-bridge-project-moves/]
#Michele Willer-Allred (2012) ''Pioneering plastic bridge opens in Santa Rosa Valley''. Scripps Interactive Newspapers Group [http://www.vcstar.com/news/2012/dec/07/plastic-bridge-in-santa-rosa-valley-opens-to/ http://www.vcstar.com/news/2012/dec/07/plastic-bridge-in-santa-rosa-valley-opens-to/]

[[Category:CIOB_competition]]
[[Category:Products_/_components]]
[[Category:Sustainability]]