Hollowcore Plank Arrived Cracked 2

[jfudo]

48" wide, 8" hollowcore planks arrived at jobsite this morning with approximately 1/3 of them have at least one crack in the top surface aligned with the cores. Contractor said it is typical, but I've never seen or heard of it happening before. I can't seem to find any guidance on how to handle it. It seems to me that the strength of the plank hasn't been compromised, and it is to receive a topping. Should this be rejected? (obviously will seriously affect the schedule of the project and winter is coming)

 

[ishvaaag]

As long you get to determine it won't affect the strength and usefulness, maybe some leeching adhesive could restore the lost continuity and strength. If the cracks are however along top wire reinforcement (that sometimes have, to limit stresses at some stage) the full adherence at those wires won't be present anymore, and maybe was not when wanted. If these wires were just useful to counteract too much tensile stress atop at some early stage maybe failed to their use, and yet the hollow core unit survived to be at the works site, then at least some of the characteristics mechanical and geometrical can be affected, say, initial camber and final deflection ... might be interesting to make some numbers about.

 

[JAE]

I would notify the precaster and let them decide whether their product has been compromised. I would also request a letter from the precaster stating it is acceptable.

I don't initially see a problem as long as the cracks are parallel with the span.

 

[rapt]

jfudo,

And if you do use them, make sure they have continuous support over the full width as they obviously have no transverse load distribution capacity!

 

[hokie66]

If the longitudinal cracks are only in the top, and there is a bonded topping to go, I wouldn't worry about it. There is another recent thread about longitudinal cracking, although this one involved cracking both top and bottom in partial panels.

thread589-213929

 

[jfudo]

Thanks everyone. It turns out there are only a couple with cracks, the person that relayed the info to me was over-reacting just a little. As JAE said, we put the issue back in the hands of the manufacturer, only because we can. It shouldn't be a problem, there is no full width support issues or anything like that.

 

[sabapathy1]

Find the attachment of pci manual for fabrication and shipment cracks in hollowcoreslab. this will help you to analyze your cracks are acceptable or not

 

[diazmeyer]

You can think of it this way jfudo, you can cut slabs longitudinally along the cores without compromising strength. (ie. two slabs cut at 24" widths, acting together should behave mechanically as the original single 48" width slab, with and without topping).
For modulation purposes you have slabs cut longitudinally at various widths as to be able to cover the whole floor area with slabs, without compromising the strength of the floor.
However, one thing to watch out for, is that depending on how the cracked slabs are manipulated into position at the site they could break longitudinally when manipulating them dropping unexpectedly.
In any case I would sugest contacting the precaster to clear any doubts you might have.

Best wishes