T-Beam Effective Flange Width (ACI 318-19 6.3.2)
The slab width acting with a T-beam web: overhang = smallest of 8 hf, sw/2, ln/8 (interior; both sides) or 6 hf, sw/2.
Example
You enter
- Web width bw (in) 12
- Flange (slab) thickness hf (in) 4
- Clear span ln (in) 240
- Clear distance to adjacent web sw (in) 48
- Beam type interior
You get
- Overhang (in) 24
- Effective flange width be 60.0 in
Details, formula, and sources
The slab width acting with a T-beam web: overhang = smallest of 8 hf, sw/2, ln/8 (interior; both sides) or 6 hf, sw/2, ln/12 (edge; one side). 12 in web, 4 in slab, ln 240, sw 48 -> be 60 in interior (sw/2 governs), 32 in edge (ln/12 governs). A design aid; the engineer of record governs.
interior: overhang = min(8 hf, sw/2, ln/8), be = bw + 2 overhang; edge: overhang = min(6 hf, sw/2, ln/12), be = bw + overhang.
The ACI 318-19 6.3.2 effective flange width of a T-beam, by name.
ACI 318 is readable free through the ACI online reading room at concrete.org; the 6.3.2 effective-flange provisions are in the published code.
Estimate. AHJ and licensed professional govern.
Field names used by the API: bw_in, hf_in, ln_in, sw_in, beam_type, overhang_in, be_in
- Interior overhang min(8 hf, sw/2, ln/8); be = bw + 2 overhangACI 318-19 6.3.2.1
- Edge overhang min(6 hf, sw/2, ln/12); be = bw + overhangACI 318-19 6.3.2.1
- Compression flange only the effective width acts as the flange in flexurescope of this tile