Cast-In Anchor Tension Concrete Breakout (ACI 318-19 Ch. 17)
Concrete breakout capacity of a headed anchor in tension by the ACI 318-19 CCD method: Nb = kc lambda sqrt(f'c) hef^1.5 (kc 24 cast-in / 17 post-installed), edge-modified to Ncb and design phiNcb. The hef^1.5 cone and near-edge knockdown that anchor-embedment never checks; a near edge can cut capacity 25% before the steel yields.
Formula and source
Nb = kc lambda sqrt(f'c) hef^1.5 (kc 24 cast-in, 17 post-installed); ANco = 9 hef^2; psi_ed = 0.7 + 0.3 ca1/(1.5 hef) when ca1 < 1.5 hef; Ncb = (ANc/ANco) psi_ed Nb; phiNcb = 0.65 Ncb.
The ACI 318-19 Section 17.6.2 concrete breakout strength in tension (CCD method), by name.
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