The applications of natural fibre/polymer composites in civil engineering are mostly concentrated on non-load bearing indoor components due to its vulnerability to environmental attack. This paper evaluates the characteristics of several natural fibre composites exposed to moisture, thermal, fire, and ultraviolet degradation through an extensive literature review. The effects of chemical additives such as fibre treatments, fire retardants and UV stabilizers are also addressed. Based on the evaluation conducted, optimum fibre content provides strength in a polymer composite but it also becomes an entry point for moisture attack. Several fibre treatments are also being used to improve fibre/matrix interface, thereby increasing moisture durability. However, the treated fibres were found to behave poorly when exposed to weather. The addition of UV stabilizers and fire retardants are suggested to enhance outdoor and fire performance of natural fibre/polymer composite but compromises its strength. Therefore, from the collected data and various experimental results, it was concluded that an optimum blend ratio of chemical additives must be employed to achieve a balance between strength and durability requirements for natural fibre composites. Dear EditorI would like to submit a paper entitle of "Degradability of Polymeric Composites Based on Natural Fibres" to the materials and design. This paper address important issues related to the degradation of natural fibres in polymeric composites. I believe the paper has interest to the reader of the journal and will be beneficial for many researchers in the field of materials and design considering the degradation of polymer and bio-materials. I would like to confirm that the paper has not been sent to any journal before and not under review. I hope you can send the paper fore reviewing process. Editor: Thank you for submitting your review paper. There are no technical issues. However, there are areas of the paper that need attention as follows: 1.Include more keywords -you are allowed up to 6 keywords.The keywords have been updated and highlighted in the revised version as Keywords: natural fibres; polymer composites; civil applications; characteristics degradation; weathering. 2.Include your personal university telephone number in the contact details in the paper.In the revised version it has been included as Reference 20 is incomplete. Updated 10.Reference 37 is incomplete. Updated 11.Reference 40 is incomplete. This paper is much related to the topic and it is in press. I added the DOI: 10.1080/15440478.2012.733149 . this is accepted in the production stage 12.Reference 65 is incomplete. Removed 13.In view of the above, please check all references for accuracy and completeness. Detailed Response to Reviewers JMAD-D-12-03220R1 2All the references are cited using endnote software. This makes it easy to update and cite the references in the required format at the publication stage. 14. Remove page numbers from list of table and figure captions. Page numbers removed...

Bamboo fibre reinforced composites are not fully utilised due to the limited understanding on their mechanical characteristics. In this paper, the effects of alkali treatment and elevated temperature on the mechanical properties of bamboo fibre reinforced polyester composites were investigated. Laminates were fabricated using untreated and sodium hydroxide (NaOH) treated (4 to 8% by weight) randomly oriented bamboo fibres and tested at room and elevated temperature (40, 80 and 120 o C). An improvement in the mechanical properties of the composites was achieved with treatment of the bamboo fibres. An NaOH concentration of 6% was found optimum and resulted in the best mechanical properties. The bending, tensile and compressive strength of this composite is 44.2, 21.0, 111.2 MPa, respectively while the stiffness is 4.0 GPa which are 7, 10, 81, and 25%, respectively higher than the untreated IntroductionSynthetic fibres such as glass, carbon and aramid have been used for several years in many applications varying from aerospace components to civil infrastructures. However, the high production and material costs of these fibres limit their wider use for the development of composite materials. As a result, there is an increasing interest in utilizing the less expensive natural fibres as reinforcement in composites because of their added advantages such as lightweight, renewability and biodegradability. Joshi et al.[1] also revealed that natural fibres are environmentally superior to glass fibres making them an emerging and realistic alternative to synthetic fibres in some engineering applications. It is anticipated therefore that the use of sustainable natural fibres in the development of new generation composites will be a necessity and will play a crucial role in the near future.Among the well-known natural fibres, bamboo has one of the most favourable combinations of low-density and high stiffness and strength [2]. Nugroho and Ando [3] indicated that these properties of bamboo make them a promising material for the manufacture of various engineered composite products. However, it is only in recent years that the interest in utilising bamboo as reinforcing materials for composites is increasing because of limited availability of the fibres [2]. This is because it is technically difficult and expensive to extract long and straight bamboo fibres [4][5]. Another significant challenge in using bamboo is the inherent flaws within fibres which reduce their compatibility with polymer matrices resulting in poor mechanical properties of the composites [6]. This is due to the hydrophilic nature of natural fibres and the hydrophobic nature of the polymer matrix but their poor compatibility can be improved by fibre surface modifications using chemical treatments.While many researchers have developed composites with natural fibres, the work on bamboo fibre reinforced composites is still very limited. Most of the studies focused mostly on tensile strength characterisation, thus Khalil el at. [5] suggested that more anal...

The flexural behaviour of a new generation composite sandwich beams made up of glass fibre reinforced polymer skins and modified phenolic core material was investigated. The composite sandwich beams were subjected to 4-point static bending test to determine their strength and failure mechanisms in the flatwise and the edgewise positions. The results of the experimental investigation showed that the composite sandwich beams tested in the edgewise position failed at a higher load with less deflection compared to specimens tested in the flatwise position. Under flexural loading, the composite sandwich beams in the edgewise position failed due to progressive failure of the skin while failure in the flatwise position is in a brittle manner due to either shear failure of the core or compressive failure of the skin followed by debonding between the skin and the core. The results of the analytical predictions and numerical simulations are in good agreement with the experimental results.

No abstract

No abstract