Slab On Grade Toughness and Additional Reinforcing
Slab On Grade Toughness and Additional Reinforcing
(OP)
I have a project where an owner is wanting a slab-on-grade designed for an industrial application. This client will be operating heavy machinery on the slab-on-grade, such as tracked excavators....and will occasionally have dumptrucks and forklifts running atop this slab-on-grade. Also, part of this slab-on-grade will support 55 gallon drums stacked (2) high.
With all that said, I have requested a subgrade modulus recommendation from the geotechnical engineer of which I will use when I design the structural reinforcing for the slab. The question I have is, how do you guys toughen the surface of a slab such as this, to help it last for a decent period of time, given the surface will be subject to a pretty abrasive user?
I've been thinking about using fibermesh (such as Novomesh 950) as a secondary reinforcing in this slab, to help toughen the surface and reduce the amount of drying and shrinkage cracking....but I'm not sure if I should go this route, go the route of steel fiber reinforcing, or perhaps use some other method of toughening all together.
Or does the slab even need toughening on the surface?
What are your thoughts?
With all that said, I have requested a subgrade modulus recommendation from the geotechnical engineer of which I will use when I design the structural reinforcing for the slab. The question I have is, how do you guys toughen the surface of a slab such as this, to help it last for a decent period of time, given the surface will be subject to a pretty abrasive user?
I've been thinking about using fibermesh (such as Novomesh 950) as a secondary reinforcing in this slab, to help toughen the surface and reduce the amount of drying and shrinkage cracking....but I'm not sure if I should go this route, go the route of steel fiber reinforcing, or perhaps use some other method of toughening all together.
Or does the slab even need toughening on the surface?
What are your thoughts?






RE: Slab On Grade Toughness and Additional Reinforcing
RE: Slab On Grade Toughness and Additional Reinforcing
Check out some of these topics for some ideas:
http://www.eng-tips.com/viewthread.cfm?qid=193614
http://www.eng-tips.com/viewthread.cfm?qid=103297
http://www.eng-tips.com/viewthread.cfm?qid=337852
http://www.eng-tips.com/viewthread.cfm?qid=32464
Professional and Structural Engineer (ME, NH)
American Concrete Industries
www.americanconcrete.com
RE: Slab On Grade Toughness and Additional Reinforcing
1. Concrete with 4000 psi + compressive strength.
2. Highest quality subgrade preparation.
3. Reinforced (with rebar) concrete.
4. Steel fibers in addition to adequate rebar.
Also, agree with hawkaz to use doweled joints.
Close space the joints, as if the concrete had no reinforcing.
To this, list suggest making the slab 12" thick (minimum) to allow meaningful use of top and bottom rebar mats (IMHO, anything less than 12" thick the top and bottoms mats are too close together for beneficial use). The issue is not necessary strength - it's keeping the slab rigid.
Also, insist on true wet curing, not moist curing, not curing compound - and do so continuously for 7 to 10 days.
For heavy duty slabs on grade (including some tracked vehicle use) at electric generating stations, we had a minimum design: 12" thick, #4 rebar @ 12", each way, top and bottom.
www.SlideRuleEra.net
www.VacuumTubeEra.net
RE: Slab On Grade Toughness and Additional Reinforcing
RE: Slab On Grade Toughness and Additional Reinforcing
One thing I've seen done in the past was embed steel floor grating in areas that fork trucks and tracked vehicles have to make sharp turns. Straight runs usually have much less wear due to vehicles.
Professional and Structural Engineer (ME, NH)
American Concrete Industries
www.americanconcrete.com
RE: Slab On Grade Toughness and Additional Reinforcing
RE: Slab On Grade Toughness and Additional Reinforcing
Expensive, but in some cases, worth it.
RE: Slab On Grade Toughness and Additional Reinforcing
Professional and Structural Engineer (ME, NH)
American Concrete Industries
www.americanconcrete.com
RE: Slab On Grade Toughness and Additional Reinforcing
RE: Slab On Grade Toughness and Additional Reinforcing
Dave
Thaidavid
RE: Slab On Grade Toughness and Additional Reinforcing
Professional and Structural Engineer (ME, NH)
American Concrete Industries
www.americanconcrete.com
RE: Slab On Grade Toughness and Additional Reinforcing
Emerytop
MasterTop
Super Euco Top
You can place them quite thick and they're very abrasion resistant. I've used 2" toppings with no negative reports. I guess you could go thicker. The product tech reps should be able to provide useful life based on different scenarios and thicknesses.
RE: Slab On Grade Toughness and Additional Reinforcing
Professional and Structural Engineer (ME, NH)
American Concrete Industries
www.americanconcrete.com