Why is the middle portion of concrete removed in a hollow core slab?
This reduces deflections compared to structures with reinforced concrete, because the entire hollow core slab section contributes to resisting the loads. When cracking is eliminated, reinforcement will be better protected from corrosion, enabling a longer life span for the structure.
Why is hollow core slab used?
In general hollow-core slabs are one of the most sustainable products in construction, because less material – less cement, less water and less steel – are needed for manufacturing them compared to cast-in-situ. Also, the voids of the slabs make the production more material-efficient.
How are hollows used in hollow core slabs?
In the cross part of hollow-core slabs, concrete is utilized just where it is really required. Zones where solid acts just as counterbalance are supplanted with hollows. For example, in 200-mm hollow-core slabs, 49.9 percent of the cross-segment comprises voids.
What is the PCI manual for hollow core slabs?
For the architect or consulting engineer, this manual is intended as a guideline for working with hollowcoreslabs,aguidefortheuseandapplicationofhollowcoreslabsandanindicationofsome of the limitations of hollow core slabs.
How are hollow core floor planks to be cast?
Hollow Core floor planks shall be cast on a long-line bed by an approved machine and mechanically compacted. The top surface shall be finished as cast by the machine or intentionally-roughened to achieve the specified bond characteristics of the topping or other finish applied after erection.
What is economy of generalized hollow core system?
The economy of the generalized hollow core system is in the quantity of slabs that can be pro- ducedatagiventimewithaminimumoflaborre- quired. Eachslabonagivencastinglinewillhave the same number of prestressing strands.