Evaluation of durability of natural fibre reinforced cement mortar composite- A new approach

‘Toughness’ of a composite generally based on the ‘toughness indices’ evaluated by flexural tests as contemplated in several codes (ASTM, ACI, JCI-SF4/JSCE-SF4) may not be appropriate/realistic for natural fibre cement composites containing low modulus fibres like sisal, coir etc., due to several reasons. Further, durability of natural fibre cement composite can be evaluated on the basis of flexural toughness (FT) and it has a special significance. Toughness of a natural fibre composite can also be evaluated by impact tests, which helps in realistic assessment of ductility of the above composite. Evaluation of durability of a natural fibre composite by residual impact strength (Irs) and flexural toughness index (IT) and their comparison are presented and discussed. Irs values could be used to assess the durability of natural fibre composites, than, the conventional ‘toughness indices’ used for composites, in general.