Civil Engineering Reference
In-Depth Information
Table 1 Examples of installed insulations in buildings
Building components
Walls
1. Exterior: installed in the exterior walls
2. Interior: installed in the interior surface of the walls
3. Ventilated: installed in the direct contact with the wall and separated from the lining
4. Gap: installed between two vertical elements
Roofs
1. Intrados: installed directly on the pitch structures
2. Under the outer skin (warm roof): installed just below tiles, pantiles or slabs
3. Under the outer skin (vented roof): placed under the vent
Floors
1. Floors on the ground and vented crawl space: installed on the extrados of the floor
2. Insulation of floor intrados (or lower surface): insulation of the floor which looks out
onto porticoes or open spaces
3. Insulation of floor extrados (or upper surface): insulation of floor covering open spaces
or basements
The fibres, both organic and inorganic, may be bonded together. Examples of
insulation materials are fibreglass and mineral wool.
Further hierarchical organization of fibrous insulations can be grouped according
to the properties and origins of the fibres that they are made out of as organic,
inorganic and advanced fibres. At the organic natural level, fibres can be divided
broadly into two categories as natural and man-made, or synthetic, fibres, such as
oil-derived fibre, while natural fibres can be further subdivided as vegetable-based
and animal-based fibres.
Vegetable fibres, also called plant fibres or lingnocellulosic fibres, are those that
originate from plants and have plant anatomy. They are characterized by light
weight, low thermal conductivity, strong tension, superior acoustic resistance,
flexibility and low processing cost. As a potential energy-efficient and sustainable
source for NZEBs/ZEBs in insulation industry, vegetable fibres would open up a
new potential market for building construction materials as already demonstrated
in building industrial application (Bisanda
1993
). From a production process point
of view, it has been reported that the energy needed for production of vegetable
fibres is, on average, more than half of the amount needed for synthetic fibres
(Cristaldi et al.
2010
). This figure highlights a high perspective for vegetable fibre
markets. This chapter will focus on vegetable fibres.
3 Vegetable Fibres and Manufacturing Process
3.1 Vegetable Fibres
All plants are made up from cells. When a cell is very long in relation to its width,
it is called a fibre (Olesen and Plackett). Vegetable fibres have long cells char-
acterized by relatively thick walls and narrow central cavities. Different plants
