“Effects of natural fibres reinforcement in lime plasters (kenaf and sisal vs. Polypropylene)”

Nowadays the tendency to realize environment-friendly products is becoming more widespread to
ensure sustainable and smart development.
The synthetic fibres, frequently used, are harmful to the environment because they are non-degradable
and non-renewable. Their use has resulted in an increase of oil consumption. Therefore, the possibility of
replacing them with natural fibres becomes increasingly concrete confirmed by the researches and inves-
tigations carried out.
In this work three lime based plasters were prepared and analysed to evaluate the influence on their
performance of different fibres used as reinforcement. In particular each plaster was realised by adding
to the mortar the same amount (i.e. 0.2% w) of polypropylene, sisal (
Agave sisalana
) and kenaf (
Hibiscus
cannabinus
) fibres, respectively. Then, compressive and bending strength, resistance to freeze/thaw con-
ditions and to marine environment (by performing salt spray test) of lime plasters were investigated.
On the basis of experimental results, natural fibres can be considered as a valid alternative to polypro-
pylene ones as reinforcement of lime plasters. In particular, the decrease of mechanical properties due to
freeze/thaw cycles is comparable under flexural load condition for all plasters analysed in this work,
while the decrease of compressive strength, shown by plasters reinforced with sisal fibres, is lower than
other ones. Moreover, thanks to their higher hydrophilicity, the plasters reinforced with natural fibres
present low weight loss after ageing time in salt spray environment than ones with polypropylene.