Hollow core plank diaphragm action

[wompa1]

I was wondering if any one knew where to find info on the diaphramatic action of the hollow core precast plank, with and without topping.

I realize that with a topping the plank will act as a rigid diaphragm, but without a topping is the plank a flexible diaphragm? I know it depends on deflection, but how does the shear transfer between planks without topping? Can the friction from the grout between the planks transfer that load?

Any help would be greatly appreciated.

 

[JAE]

Go here:

Spancrete HC Diaphragm Research Notes

 

[UcfSE]

See chapter 4 here.