Ply board repetition

[VIDHYA SAGAR]

1. How many times we can re-use ply boards for shuttering purpose.
Is there any specification / codes available for this.
Their is no details available with manufacturers test certificate in this regard.
Types of ply boards for shuttering and how many times it will withstand - details required.

2. What is the minimum radius we can make by using standard size ply wood?

Any one explain please.

Regards.
Vidhyasagar.

 

[rameshchandrapatel]

Any 12 mm shuttering plywood can be used for max. 12 times depending on how it is used.

 

[VIDHYA SAGAR]

Thanks.
How can we calculate the minimum radius we can make by using standard size ply wood?

 

[Dnyan Deshmukh]

Fist of all, have close look at the plywood supplied to you.

It will have the name of company, IS code printed to which it confirms and the type of plywood it is.

All construction plywood confirms to IS 4990 unless you are using marine plywood.

There are three types of plywood manufactured confirming to IS 4990 published in 2011

CS - Plywood for concrete shuttering work (Plain)

CSC - Plywood for concrete shuttering work with plastic coating (Coated)

CSFF - Plywood for concrete shuttering work with suitable overlay (Film Faced)


About the repetition of Plywood

IS code state that all above plywoods can be used repeatedly but it does not say about how many times you can reuse it.

Perhaps, it states the reuse of plywood depends on care taken in handling of plywood and also as per how you follow instruction provided by manufacturer.

So for getting the repetition value of plywood supplied to you, kindly do contact the manufacture and ask him (Again if he say you can use 7 times on each face, it does not mean that, even worker handle it badly it should give the stated result)


Minimum Radius to which plywood can be bend

IS 4990 states the bending radius to which we can bend the plywood (Those values are when plywood is dry condition)

For 6mm thick plywood
When you bend across the grains of outer pile - You can bend it to Minimum Radius of 0.9 Meter
When you bend parallel to grains of outer pile - You can bend it to Minimum Radius of 1.25 Meter

For 9mm thick plywood
When you bend across the grains of outer pile - You can bend it to Minimum Radius of 1.65 Meter
When you bend parallel to grains of outer pile - You can bend it to Minimum Radius of 2.15 Meter

For 12mm thick plywood
When you bend across the grains of outer pile - You can bend it to Minimum Radius of 2.55 Meter
When you bend parallel to grains of outer pile - You can bend it to Minimum Radius of 3.30 Meter


Plywood which do not have any coating on it (Plain plywood) can bent further more with less radius by soaking in cold or hot water with temperature less than 70 degree before fixing it.

 

[VIDHYA SAGAR]

Thanks for your brief reply. It is very useful to me sir.