Civil Engineering Reference
In-Depth Information
as load-bearing wall, roofing tiles and ceiling plates (Agopyan et al.
2005
). Details
can be found in the above-described reviews. In brief, utilizing natural fibres for
the insulation of buildings has become one of the increasingly practiced techniques
in building industry in recent years.
Natural vegetable fibres, traditionally for filling and reinforcing buildings
composites, have attracted increasingly more attention for building insulations due
to their superior thermal and acoustic insulation properties, high flexural and
tensile modulus, low density, low thermal expansion coefficient and added envi-
ronmentally preferable properties, such as renewable recycled, low manufacturing
cost among many others. Various environment-friendly insulations and building
constructions have been developed and favourably investigated using various
vegetable fibres, for example, cotton stalk fibres (Zhou et al.
2010
), date palm
wood (Agoudjil et al.
2011
), hemp (Le et al.
2010
), straw bale (Ashour et al.
2010
),
combined jute, flax and hemp (Korjenic et al.
2011
), sugar cane bagasse fibres
(Onesippe et al.
2010
), banana (Paul et al.
2013
), banana/sisal hybrid fibre (Idicula
et al.
2010
), banana and coir (Sathishkumar et al.
2012
).
In fact vegetable fibres provide all manners of reinforced materials in building
constructions, such as bricks, cement, aggregates, steel, aluminium, wood, clad-
ding, partitioning materials. Examples of vegetable fibres that have been invested
and reported in the literature are sisal, wood, barley straw, flax, hemp, jute, pine-
wood fibre, rice husk, sawdust, luffa sponge, paper sludge, coconut, kenaf, kapok/
cotton, pineapple leaf, basalt, vetiver, bio flour, bamboo, date palm, cotton waste,
dried sludge collected from an industrial wastewater treatment plant, rice husk ash,
granulated blast furnace slag, wood sawdust, processed waste tea and waste forms
from different vegetable fibres (Kazragis
2005
; Pacheco Torgal et al.
2011
; Raut
et al.
2011
; Madurwar et al.
2013
), to cite a few reviews. Bouhicha et al. (
2005
)
investigated the usage of composite soil reinforced with chopped barley straw and
soils acting as a thermal insulation for indoor temperature under extreme weather
conditions. More reviews of the cellulosic-based materials in composites were
given by Bledzki and Gassan (
1999
) and Malkapuram et al. (
2008
).
Despite significant increases in production, application and development of
vegetable-fibre-reinforced composites remain many challenges. Glass fibres still
dominate the composites industry.
The main disadvantages of using natural fibres, in general, are their high
hydrophilic behaviour and incompatibility between them (hydrophilic fibres) and
hydrophobic matrices, which demand appropriate physical and chemical treatments
to enhance the adhesion between them, and which in turn will ultimately affect the
overall properties of the composites. The large variation in the properties of natural
vegetable fibres is another important disadvantage. For example, concerns have
been raised over the years for the durability of the fibres in the composites with
alkaline since alkaline weakens vegetable fibres. The composites may undergo a
reduction in strength and toughness as a result of the weakened fibres. Another
major drawback of composites from vegetable fibres is the reduced processing and
practical temperatures, such as product extrusion and injection temperatures due to
sensitivity of the composite from both fibre and matrix. The thermal degradation of
