Recycling Facility 1

[AUCE98]

I am looking for a reference that may provide some guidance for live load of a recycling facility floor. At this point we are estimating that the controlling factor for thickness of the slab will be a wheel load of front end loader of an undetermined capacity. My initial guess is 400-500 psf and a slab thickness of 6-8 inches. Any assistance would be appreciated.

Regards,

AUCE98

 

[civilperson]

Steel wheels on forklift truck have 7-10 kips on two line/point loads.

 

[Ron]

The floor is a high cycle pavement. With the number of cycles governed by the queueing and turning operations of the loader. This is an industrial pavement problem.

Design the slab for two things...strength and durability to withstand the high abrasion for this application.

1. The imposed traffic loads. Get loading info from the front loader mfr. Assume fully loaded bucket on 1/2 the cycles.
2. In the staging/queueing area, the haul trucks will add wheel loads. Find out the number of loading/unloadings per day, determine if 5-day or 7-day operation, determine length of work shifts, then compute expected number of loads based on wheel loads for each piece of equipment.
3. Decide on the expected life of the slab then solve the pavement equations using the PCA method or the AASHTO method for rigid pavements.
4. Next consider the durability for the expected abrasion. Specify a relatively high strength concrete (5000 psi or greater), a low water-cement ratio, and control the placement such that water is not added indiscriminately at the site and thickness is maintained within ACI tolerances.
5. Design joints for load transfer and control of cracking. For the anticipated thickness (8 to 10 inches), the joints should be no more than 15 feet apart. Consider doweling the joints rather than using a "key" design. Follow AASHTO procedures for the jointing and dowels.

 

[hokie66]

I think Ron's suggestion of a 8 to 10" floor is more like it for thickness, and agree with his recommendation as to how to design the thickness. But I disagree as to joint spacing. Joints are the main problem with industrial floors, so the fewer, the better. I would make them at least 30 ft apart, maybe 40. Shrinkage cracks generally present less problems than do construction joints. Agree with his comments about concrete quality, but for a floor like this, toughness/impact resistance of the surface is all important, and that can best be improved by adding steel fibres to the mix. To control shrinkage cracks, use about .5% reinforcing steel.

 

[AUCE98]

Thank you all for your insight.