What is TRADA?

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Implications of Alternative Solution Choices
Implications of Alternative Solution Choices -
Technical Implications - Manufacturing
Implications - Aesthetic Implications -
Environmental Implications - Economic
Factors
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Implications of Alternative Solution Choices
Technical Implications The benefits realised
(and a portion of the associated costs) is
determined as a function of the materials used,
including - reinforcement type - adhesives used
- timber material that is to be reinforced
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Implications of Alternative Solution Choices

• Technical Implications reinforcement type
• The scope of this study includes
• glass fibre reinforced plastic (GFRP)
• carbon fibre reinforced plastic (CFRP)
  reinforcement.
• pre-formed composites (e.g. pultruded rods or
  plates)
• fabrics that are wetted out and bonded with
  structural adhesives in one process.

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Implications of Alternative Solution Choices
The properties of the composites produced vary
massively between generic types and commercial
products of similar general description
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Implications of Alternative Solution Choices
It can be seen that in terms of strength and
stiffness, carbon FRP products generally
out-perform glass FRP products.
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Implications of Alternative Solution Choices

• Technical Implications adhesives used
• greatest potential for successful application in
  structural timber reinforcement are gap filling
• structural epoxies
• polyurethanes

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Implications of Alternative Solution Choices

• Technical Implications timber material
• In this project, the following timber materials
  have been considered
• Sawn softwood
• Sawn hardwood
• Commercial softwood glulam
• LVL
• The scope for reinforcement has been found to be
  greatest in larger section members formed by
  commercial softwood glulam.

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Implications of Alternative Solution Choices

• Manufacturing Implications
• With regard to technical and manufacturing
  issues, three key areas require consideration
• Form of reinforcement, in terms of the manner in
  which the reinforcement is incorporated and its
  location within the timber section
• Fabrication process issues, including machining,
  bonding and handling requirements
• Integration of reinforcement within the sequence
  of member manufacture

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Implications of Alternative Solution Choices
Form of Reinforcement - location of the
reinforcement material - manner in which it is
incorporated These define the fabrication
process for the reinforced timber element and the
limitations upon the point in the manufacture
sequence at which the reinforcement can be
practically incorporated.
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Implications of Alternative Solution Choices

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Implications of Alternative Solution Choices

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Implications of Alternative Solution Choices

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Implications of Alternative Solution Choices
Aesthetic Implications For bonded in rods or
plates, the reinforcement is concealed from view
and therefore has no aesthetic impact. For
surface bonded systems, or where the
reinforcement is placed in recesses or grooves at
the surface of members, it will be exposed and
therefore will affect the appearance of the
timber. Aesthetics of revealed surfaces can be
critical factor in choosing a system. For
example, an uneven surface (sometimes described
as an "orange peel" effect) can result if surface
bonded fabric reinforcement is used. This can be
quite critical, especially on architect designed
special structures where the appearance of timber
is a key factor in its choice. There is the
possibility of use of timber veneer or thin
plywood as a finish applied over any surface
fixed FRP to avoid such visual problems. In
either case, these would be heavily reliant upon
imported products.
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Implications of Alternative Solution Choices
Environmental Implications
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Implications of Alternative Solution Choices

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Implications of Alternative Solution Choices
Timber structures have good environmental
profiles Based upon The Green Guide to
Specification, in all of the primary
superstructure categories timber options scored
well on the rating system. It was identified that
this is linked to the fact that the lower mass of
materials and the lesser degree to which they are
the product of intensive resource and energy
consuming manufacturing process, promoting a more
favourable environmental profile. A recent
life-cycle analysis of timber products, using an
industry-agreed approach, showed that timber has
a relatively low environmental impact in many
applications when taking the impacts of
replacement, maintenance and disposal into
account. Although it can be argued that the
introduction of FRPs and adhesives compromises
the environmental profile of timber solutions, it
should be remembered that the volume of these
materials is very low as a percentage of the
volume of timber employed. Also the benefits of
reinforcement may lead to smaller members,
requiring less timber in the first instance and
leading to knock-on effects, such as reduced
storey heights, finishing and cladding areas,
which in turn reduce the overall material
consumption of the building.
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Implications of Alternative Solution Choices

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Implications of Alternative Solution Choices

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Implications of Alternative Solution Choices

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Implications of Alternative Solution Choices

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Implications of Alternative Solution Choices

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Implications of Alternative Solution Choices
- Economic Factors There are numerous economic
factors concerning lightweight reinforced timber
structures. These include overall economic
feasibility of innovation whole life cost
impact disposal of products projected future
discounted values of necessary investments
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Implications of Alternative Solution Choices

• Overall Economic Feasibility of Innovation
• Innovation is often regarded as the driver for
  introduction of construction economies and
  advancing labour productivity. This is true for
  certain types of innovations, but there are also
  limitations due to the economic infeasibility of
  such innovations. This is particularly the case
  in the segments of construction industry that are
  more fragmented.
• Therefore, it can be seen that there are several
  major barriers to innovation in the technological
  process of construction
• demand instability
• industrial fragmentation
• building codes

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Implications of Alternative Solution Choices

• Whilst the economic factors above present an
  overall scenario whereby the adoption of
  reinforced timber apparently faces massive
  hurdles to acceptance and use as an economically
  viable alternative to existing materials, there
  are however examples of use of FRP reinforcement
  in actual structures, which have been
  economically justified
• Repair of Timber Structures numerous instances
  can be found of reported use of FRP in repair and
  renovation projects, for example
• A number of examples are reported at
  www.rotafix.co.uk including reinforcement of
  timber highway bridges in Canada, using epoxy
  bonded GFRP pultrusions. Here reinforcement costs
  of CAN120,000 (? 49,090) were identified,
  compared to CAN800,000 (? 327,250) replacement
  costs.
• Numerous timber bridge repair examples also exist
  in Europe, including surface bonded CFRP
  laminates
• In a cost assessment of repair of timber beams in
  historically important timber structures, bonded
  in GFRP systems were identified as being less
  time consuming than alternative methods
• FRP in new-build examples found of application
  of FRP reinforcement in new-build structures are
  less numerous. One example has been reported of a
  50m twin-span reinforced glulam bridge, where the
  reinforced solution was identified to save
  superstructure costs in the region of 24
  compared to a standard glulam structure and 10
  compared to a precast concrete alternative. The
  reduced weight (reinforced timber being less than
  10 of the weight of the concrete solution and
  using a third less timber than the non-reinforced
  glulam) also introduces further savings in
  relation to transportation costs and foundation
  requirements.

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Implications of Alternative Solution Choices
The overall feasibility of innovation through
introduction of this technology is bolstered
through recent trends towards incorporation of
non-ferrous reinforcement in concrete structures.
The use of FRPs in reinforced concrete bridges is
estimated to increase project costs by between 4
and 8 , but is offset against significant
benefits over steel reinforcement (e.g. typical
weight savings of 15). Significant investment in
research and development has resulted in
development of recognised design methods and
increased acceptance by construction
professionals. This has seen a trend of increased
specification over the last decade 250 tonnes
of FRP concrete reinforcement were specified in
2002 addressing 1.7 of the potential UK market
of 15,000 tonnes. Approximately 5,000 tonnes are
estimated as being specified in the USA and
Japan. Therefore, whilst there are significant
barriers to uptake, there is increasing designer
awareness and acceptance of the materials and a
small but growing level of proven application.
So, whilst supported by strong technical and
economic advantage, the feasibility will be
dependant upon development and marketing of
industrialised FRP reinforced timber products to
create and satisfy market demand in order to
offset initial start-up costs.
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Implications of Alternative Solution Choices
Whole Life Cost Impact Whole life costing
incorporates this information in calculation
according to the formula WLC IC OC
DC WhereIC initial cost capital and
labour cost required necessary to purchase and
install a productOC operational costs
costs incurred during the operational life DC
disposal costs Disposal of Products DC ?
(K L O) Where DC Disposal cost for
component K cost of capital to deconstruct L
cost of labour to deconstruct O cost of
overhead to deconstruct
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Implications of Alternative Solution Choices
Projected Future Discounted Values of Necessary
Investments C / (1r)t Where C current costr
rate of interest or discount ratet time in
years The design life of structures within the
scope of application of FRP reinforcement
considered in this study will generally be in the
range 40-60 years . The suggested component
design life data presented in ISO 15686-1
suggests that the main structural components in
which FRP reinforcement is likely to be employed
would have a design life equal to the building
design life. It is not intended in the context
of this study to increase service life through
incorporation of reinforcement. Therefore, the
reference service life (RSLC) of both the
reinforced and non-reinforced components will be
taken as the same. Therefore, whilst the future
discounted values of members over this time range
are a very low percentage of the present value,
the future discounted adjustment of value in both
the reinforced and non-reinforced members will be
of similar effect.