Bamboo instead of Steel ?

Bamboo instead of Steel?

The title “Bamboo instead of Steel” is a very popular dialogue in our country, Bangladesh because of an incident of using bamboo instead of steel.

Here, I try to interpret the using scope of bamboo as reinforcement from a different scientific perspective or experimental results of the conference paper.

Bamboo is used as a structural element from the ancient age in South Asia, East Asia, and the South Pacific traditionally. Many suspension bridges using bamboo in the previous era can be seen in these parts.

“In bamboo, as in other grasses, the internodal regions of the stem are usually hollow and the vascular bundles in the cross-section are scattered throughout the stem instead of in a cylindrical arrangement. The dicotyledonous woody xylem is also absent. The absence of secondary growth wood causes the stems of monocots, including the palms and large bamboos, to be columnar rather than tapering.” ^[1]

 Bamboo is a natural building material with a high strength-to-weight ratio useful for structures. But the question is how strong it is compared to other available elements.

Bambusa Vulgaris (Wikipedia)

According to the conference paper titled as“Mechanical properties of different bamboo Species”^[2]  where they experiment and compare the strength among spruce Wood, steel, and treated bamboo (Bambusa Vulgaris), the compressive strength or yield strength of bamboo is 78 N/mm² whereas this strength is 250 N/mm² and 43 N/mm² for steel and spruce wood respectively.

In the tensile strength section steel made the highest as 410 N/mm² where spruce wood showed the lowest among as giving tensile strength as 89 N/mm². But bamboo gave a much higher result than wood attaining 233 N/mm² as tensile strength.

For elastic modulus, the values were 21000 N/mm²,20000 N/mm² and 11000 N/mm² for steel, bamboo, and spruce wood respectively.

From these criteria, it can be said that wood is quite stronger than wood for construction purposes. But it is not enough capable of replacing steel as steel has higher compressive and tensile strength as well as slightly higher elastic modulus.

So, if steel is available or the authority can provide steel cost, there wood should not be used as the main reinforcement element instead of steel. On the contrary, it would be better and economical to use bamboo as reinforcement rather than wood as much better strength of bamboo.

Few papers say bamboo is stronger than some selected alloys of steel which is contradictory to the major or lion's share general experiments. Further experiments are needed to extend the use of bamboo as it has exquisite qualities like low cost and fast growth productivity. 

It can be interesting that bamboo is also used as food like Bamboo shoots, aesthetic purposes, etc. sectors.

References 

1: Wilson, C.L. & Loomis, W.E. Botany (3rd ed.). Holt, Rinehart and Winston.

2: “Mechanical properties of different bamboo species” by Dinie Awalluddin, Mohd Azreen Mohd Ariffin, Mohd HanimN         Osman, Mohd Warid Hussin, Mohamed A. Ismail, Han-Seung Lee, and Nor Hasanah Abdul Shukor Lim.

         DOI: https://doi.org/10.1051/matecconf/201713801024