**4. Thermogravimetric studies of bamboo**

*3.2.1. Tensile strength and modulus*

154 Bamboo - Current and Future Prospects

strengths.

and node strips.

Studies have been carried out to investigate the variation of mechanical properties as well as between the internodes and nodes, and the variation between different locations in the bamboo culm [43, 44]. Researchers have conducted studies on the mechanical behavior of both full size culm (round form) [45, 46] and small specimens [47, 48]. Lakkad and Patel [49] revealed that the specific strength of bamboo is greater than that of the most thermosetting resins. It was observed that bamboo is stiffer and stronger than other woods. Therefore, authors hypothesized that bamboo has remarkable potential as a structural material when consider-

Defoirdt et al. [50] assessed the tensile properties of bamboo fibers to understand, how they go well as starting material for composite material. They reported that decreasing trend in strength of bamboo fiber was observed as length was increased justifying that, with higher test lengths there are more drawbacks in the fibers that increases the chances of failure. They compared the tensile strength of bamboo with other fibers and found that tensile strength of bamboo is higher in contrast to other fibers even though the bamboo fibers were damaged during extraction process. In other study, Tan et al. [51] revealed that the tensile strength degradation of bamboo corresponds to the fiber density degradation. Authors reported the highest strengths were found to be in the regions nearer outer surfaces with higher fiber densities. However, lowest strengths correspond to the regions away from the outside surfaces with the lowest fiber densities whereas in between regions shown intermediate tensile

Li [28] also stated that tensile strength and mean Young's modulus increases with increase of cellulose content and decreasing microfibrillar angle. Rao and Rao [52] carried out a study on tensile strength as well as tensile modulus of bamboo. They reported that bamboo fibers possess highest tensile modulus as compared to other fibers viz., palm coconut and sisal fibers. In our recent work carried out on *Gigantochloa sps*, we observed that the higher tensile modulus group was *G. levis* (3793 MPa), followed by *G. wrayi* (3670 MPa) and *G. scortechinii* (3456 MPa) and the lower was *G. brang* (2661 MPa); (*G. levis* > *G. wrayi* > *G. scortechinii* > *G. brang*). There was a noteworthy difference between green and air dry sample. This might due to the fact that bamboo behaves as similar to wood whereby the mechanical properties increases with the decrease in moisture content [39]. The analysis of variance for tensile modulus at different locations exhibited a significant difference between the internode strips

Modulus of rupture is the maximum flexural stress sustained by the specimen during bending test or in other words can be defined as the maximum stress in bending that can be withstood by the outer fibers of a specimen before rupturing. Tamizi [31] reported the comparative results of modulus of rupture with reference to different position of different species of bamboo. Both dry and green sample exhibited different values of modulus of rupture. The order was (*G. scortechinii > G. wrayi > G. levis > G. brang*). It was reported that air dry samples showed

*3.2.2. Static bending (modulus of rupture and modulus of elasticity)*

ing the mechanical properties of bamboo together with its low cost properties.
