Technical Questions

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Q. I understand that ACI 318 does not address slabs-on-ground. Is a slab-on-ground that is supported by piles still considered a slab-on-ground by ACI?


A. According to section 1.4.8 of ACI 318-19, ACI 318 does not apply to design and construction of slabs-on-ground, unless the slab transmits vertical loads or lateral forces from other portions of the structure to the soil. The case you described does not appear to be a “soil-supported” slab, thus applicable provisions of ACI 318 would govern.

Note that ACI 360R presents information on the design of slabs-on-ground, primarily industrial floors and the slabs adjacent to them. The report addresses the planning, design, and detailing of the slabs. Background information on the design theories is followed by discussion of the soil support system, loadings, and types of slabs. Design methods are given for structural plain concrete, reinforced concrete, shrinkage-compensating concrete, and post-tensioned concrete slabs.


References: ACI 318-19; 360R-10

Topics in Concrete: 318 Building Code; Design; Slab

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