Using bamboo-reinforced concrete for underwater construction

[Laird Allan]

Can anyone offer me advice on using bamboo-reinforced concrete for underwater construction?

My project involves building artificial boulders for restoration of a coral reef. To save materials and increase the habitat quality, the boulders will be hollow 'shells' with holes for fish to enter. I want to use as much locally-available natural material as possible. There is abundant green bamboo in the area.

My question is that if I use bamboo to reinforce the boulders, will exposed bamboo decompose in the seawater rapidly or not? It would be ideal to have it remain strong for five years or more until organisms growing on the concrete are sufficient to strengthen the structure against collapse on their own (and the concrete itself has hardened more completely).

I can however probably arrange the reinforcement to be completely within the concrete, so as to not contact the seawater.

One further thing: what is the best way to permanently bend green bamboo? I need to get it to approximate the boulders' heights and curvature, so as to not have it pushing out of or stressing the concrete until it has hardened.

Thanks for your suggestions,
Mr. Laird Allan
Senior Program Coordinator,
Mahidol Uni. Inter. College Science Division
Koh Mak CORAL Science Director
Thailand

[Scott]

Hi,

I'm also in Thailand and have an interest in bamboo. Regarding it's use underwater, I would think it's life expectancy would greater than if it was out of water. However I doubt it will last 5 years. Bamboo is often used on fishing boats in Thailand, so I would suggest checking with fisherman to see how long it lasts.

Regarding bending bamboo, I don't have much knowledge of this, however there is a fair bit of info on this site.

I would suggest asking the locals, even though they may be reluctant to offer suggestions, my experience is that they have a lot of knowledge on working with bamboo. Also, using a method that is familar to them will make things easier.

You could also consider asking them for suggestions on the best variety to use.