ACI 318-14
Building Code Requirements for Structural Concrete (ACI 318-14) and Commentary
Reported by ACI Committee 318
ERRATA as of March 2, 2022
R8.7.5.6.2, p. 111, revised as follows:
R8.7.5.6.2 Between Outside of column orand shear cap faces, structural integrity tendons
should pass below the orthogonal tendons from adjacent spans so that vertical movements of the
integrity tendons are restrained by the orthogonal tendons. Where tendons are distributed in one
direction and banded in the orthogonal direction, this requirement can be satisfied by first placing
the integrity tendons for the distributed tendon direction and then placing the banded tendons.
Where tendons are distributed in both directions, weaving of tendons is necessary and use of
8.7.5.6.3 may be an easier approach.
ERRATA as of January 14, 2021
R2.2, p. 26, add the following variable to the commentary notation:
wn = length of the side of a nodal zone, in.
R20.6.5.1, p. 339, revised as follows:
R20.6.5.1 For recommendations regarding protection, refer to ACI 423.3R4.2 and 4.3 of Mojtahedi and
Gamble (1978) and ACI 423.73.4, 3.6, 5, 6, and 6.3 of Breen et al. (1994).
R23.3.1, p. 392, revised as follows:
R23.3.1 Factored loads are applied to the strut-and-tie model, and the forces in all the struts, ties, and
nodal zones are calculated. If several load combinations exist, each should be investigated separately. For
a given strut, tie, or nodal zone, FuFus, Fut, or Fun is the largest force in that element for all load
combinations considered.
ERRATA as of June 24, 2020
R2.2, p. 15, add the following variables to the commentary notation:
Di = diagonal compression component of shear flow resistance in concrete, lb
Md = moment due to unfactored dead load, in.-lb
Ni = axial tension component of shear flow resistance in longitudinal reinforcement, lb
po = perimeter of area Ao, in.
q = shear flow, lb/in.
εs = strain in steel
εy = yield strain of steel
τ = shear stress, psi
ERRATA as of May 12, 2020
R25.7.1.6, p. 436-437, third paragraph, revise as:
When a rectangular beam fails in torsion, the corners of the beam tend to spall off due to the inclined
compressive stresses in the concrete diagonals of the space truss changing direction at the corner as shown
in Fig. R25.7.1.6(ab). In tests (Mitchell and Collins 1976), closed stirrups anchored by 90-degree hooks
failed when this occurred. For this reason, 135-degree standard hooks or seismic hooks are preferable for
torsional stirrups in all cases. In regions where this spalling is prevented by an adjacent slab or flange,
25.7.1.6(ba) relaxes this requirement and allows 90-degree hooks because of the added confinement from
the slab (refer to Fig. R25.7.1.6(ba)).
ERRATA as of June 5, 2019
KEYWORDS, page 3, term revised as:
contract construction documents
NOTES FROM THE PUBLISHER, page 3, first paragraph, fifth sentence revised as:
Reference to this commentary shall not be made in contract construction documents.
Chapter 2, Definitions, revised as:
concrete, plain—structural concrete with no reinforcement or with less than the minimum amount of
reinforcement specified for reinforced concrete.
concrete, reinforced—structural concrete reinforced with at least the minimum amount of nonprestressed
reinforcement, prestressed reinforcement, or both, as specified in this Code.
concrete, prestressed—reinforced concrete in which internal stresses have been introduced by
prestressed reinforcement to reduce potential tensile stresses in concrete resulting from loads, and
for two-way slabs, with at least the minimum amount of prestressed reinforcement.
concrete, precast—structural concrete element cast elsewhere than its final position in the structure.
Chapter 2, Commentary Definitions, revised as:
concrete, plain—The presence of reinforcement, nonprestressed or prestressed, does not exclude the
member from being classified as plain concrete, provided all requirements of Chapter 14 are satisfied.
concrete, prestressed— Classes of prestressed flexural members are defined in 24.5.2.1. Prestressed twoway slabs require a minimum level of compressive stress in the concrete due to effective prestress in
accordance with 8.6.2.1. Although the behavior of prestressed members with unbonded tendons may vary
from that of members with continuously bonded prestressed reinforcement, bonded and unbonded
prestressed concrete are combined with nonprestressed concrete under the generic term “reinforced
concrete.” Provisions common to both prestressed and nonprestressed concrete are integrated to avoid
overlapping and conflicting provisions.
Chapter 2, Commentary Definitions,Added:
concrete, nonprestressed – Nonprestressed concrete usually contains no prestressed reinforcement.
Prestressed two-way slabs require a minimum level of compressive stress in the concrete due to effective
prestress in accordance with 8.6.2.1. Two-way slabs with less than this minimum level of precompression
are required to be designed as nonprestressed concrete.
Chapter 2, Commentary Notation, page 25, revised as:
Tburst =
tensile force in general zone acting ahead of the anchorage device caused by spreading of
the anchorage force, in.lb
Fig. R7.6.4.2, page 88, revised as (changed the word “compression” to “average compressive
stress” in annotation. Changed 7.12.3.4 to 7.7.6.3.1 and 7.12.3.5 to 7.7.6.3.2.):
7.7.2.3, page 88, revised as:
For nonprestressed slabs, Mmaximum spacing s of deformed reinforcement shall be the lesser of
3h and 18 in.
R8.1, page 93, first paragraph, reference revised as:
The design methods given in this chapter … PTI DC10.5DC20.8;
R8.4.1.2, page 97, references in the second and last sentences of the paragraph should be revised
as:
The equivalent frame method of analysis has been shown … PTI DC10.5DC20.8; …
PTI DC10.5DC20.8 provides guidance for prestressed concrete slab systems.
9.7.3.8.3, page 143, revised as:
At simple supports and points of inflection, db for positive moment tension reinforcement shall be
limited such that ℓd for that reinforcement…
Fig. R11.5.3.1, page 166, revised as:
(References to Section 14.4 changed to Section 11.5.2 and reference to Eq. (14-1) changed to Eq.
(11.5.3.1)).
Table 11.5.4.6, Equation (e), page 168, revised as:
Calculation
option
Axial force
Vc
Compression
2 fchd
Tension

Nu 
2 1 +
 f chd
Greater  500 Ag 
of:
0
Simplified
3.3 f chd +
Detailed
Tension or
compression
Lesser
of:
(a)
Nu d
4 w


N 
f c + 0.2 u  

w  1.25
wh  
0.6 f  + 
hd
c


Mu
w
−


Vu
2


Equation shall not apply if (Mu/Vu – ℓw/2) is
negative.
(“f'”corrected to “fc'” inside the square root next to 1.25λ.)
(b)
(c)
(d)
(e)
11.6.2, p. 169, revise to:
11.6.2 If in-plane Vu ≥ 0.5ϕVc, (a) and (b) shall be satisfied:
(a) ρℓ shall be at least the greater of the value calculated by Eq. (11.6.2) and 0.0025, but need not exceed ρt
in accordance with Table 11.6.1 required by 11.5.4.8.
ρℓ ≥ 0.0025 + 0.5(2.5 – hw/ℓw)(ρt – 0.0025)
(11.6.2)
(b) ρt shall be at least 0.0025
11.7.4.1, p. 170, revise as:
11.7.4.1 If longitudinal reinforcement is required for compression and if Ast exceeds 0.01Ag,
longitudinal reinforcement shall be laterally supported by transverse ties.
17.2.3.4.3(d), p. 224, revise as:
(d) The anchor or group of anchors shall be designed for the maximum tension obtained from
design load combinations that include E, with the horizontal component of E increased by Ωo.
The anchor design tensile strength shall satisfy the shear strength requirements of 17.3.1.1.
17.2.3.5.3(c), p. 227, revise as:
(c) The anchor or group of anchors shall be designed for the maximum shear obtained from
design load combinations that include E, with the horizontal component of E increased by Ωo.
The anchor design shear strength shall satisfy the shear strength requirements of 17.3.1.1.
17.3.3, p. 233, revise as:
(c) Anchor governed by concrete breakout, side-face
blowout, bond, pullout, or pryout strength
(i)
(ii)
Condition A
Condition B
Shear loads.......................... 0.75..........................0.70
Tension loads
17.4.2.2 The basic concrete breakout strength of a single anchor in tension in cracked concrete, Nb, shall
not exceed
Nb = kc λa
fc hef 1.5
(17.4.2.2a)
where kc = 24 for cast-in anchors and 17 for post-installed anchors.
The value of kc for post-installed anchors shall be permitted to be increased above 17 based on ACI
355.2 or ACI 355.4 product-specific tests, but shall not exceed 24.
Fig. R17.4.5.1, page 244, revise as:
The phrase “s1 and s2 >2cNa”
SHOULD READ
“s1 and s2 < 2cNa”
R18.2.2, Page 266, revise as:
Second paragraph, last sentence of paragraph:
The analysis assumptions described in 6.6.3.1.2 and 6.6.3.1.3 6.6.3.1 may be used to estimate
lateral deflections of reinforced concrete building systems.
Fig. R18.7.5.2, page 283, the original figure had bc1 and bc2 were in the incorrect location. Revise
as noted below:
18.10.6.2, page 295, revise as:
Walls or wall piers with hw/ℓw ≥ 2.0 that are effectively continuous from the base of structure to
top of wall and are designed to have a single critical section for flexure and axial loads shall
satisfy (a) and (b), or shall be designed by 18.10.6.3
Fig. R21.2.2b, page 343, revised so that the value of the “Compression controlled” segment of
the line labeled “Other” is “0.65”.
TABLE 22.5.8.2, Eq. (a), page 355, revised as:
Vc
[1]
Vu d p 

 0.6 fc + 700
 bwd
Mu 

(a)
(0.6 f c + 700)bw d
(b)
5 f cbw d
(c)
Least of (a), (b),
and (c):
(Subscript “p” added to “d” inside parenthesis.)
Equation 21.2.3
The denominator in Equation 21.2.3 should be 3000.
tr
 f se 
=
 db
 21 3000 
(21.2.3)
22.7.6.1, page 375, Equation (22.7.6.1b) should have a tan instead of a cot
(b)
Tn =
2 A0 A f y
(b)
Tn =
2 A0 A f y
tan  (22.7.6.1b)
ph
ph
cot  (22.7.6.1b)
22.8.3.2, page 378, Table 22.8.3.2: Ag should be A1 at the end of Eq. (22.8.3.2(a)).
Geometry of bearing
area
Bn
Supporting surface is
wider on all sides than
Lesser of
(a) and (b)
A2 /A1 (0.85 f cA g 1 )
(a)
2(0.85fc′A1)
the loaded area
0.85fc′A1
Other cases
(b)
(c)
Fig. R22.9.4.3a, p. 382, reference to equation revised as:
(22.9.4.3)
COMMENTARY REFERENCES, page 495, Post-Tensioning Institute (PTI), reference added:
DC20.8-04: Design of Post-Tensioned Slabs Using Unbonded Tendons
APPENDIX B, Provision Number 7.6.1.1, page 509, As in equations changed to Ag:
Provision SI-metric stress in MPa
number
0.0018  420
7.6.1.1
As
mks-metric stress in kgf/cm2 U.S. Customary units stress in
pounds per square inch (psi)
fy
0.0018  4200
As
fy
0.0018  60, 000
As
fy
0.0018  420
Ag
fy
0.0018  4200
Ag
fy
0.0018  60, 000
Ag
fy
APPENDIX B, Provision Number 8.6.1.1, page 509, As in equations changed to Ag:
Provision SI-metric stress in MPa
number
mks-metric stress in kgf/cm2 U.S. Customary units stress in
pounds per square inch (psi)
8.6.1.1
0.0018  420
As
fy
0.0018  4200
As
fy
0.0018  60, 000
As
fy
0.0018  420
Ag
fy
0.0018  4200
Ag
fy
0.0018  60, 000
Ag
fy
APPENDIX B, Provision Number 9.6.4.3 (a) and (b), second column, second equation, p. 510,
revised as:
A ,min 
A ,min 
1.33 f c Acp
fy
1.33 f c Acp
fy
 25bw 
f yt
−
 ph
 f yt 
fy


 1.75bw 
f yt
−
 ph
 f yt 
fy


APPENDIX B, Provision Number 12.5.3.4, p. 511
Add to first column:
Vu  0.66 Acv fc
Add to second column:
Vu  2.1Acv
f c'
Add to third column:
Vu  8 Acv
f c'
APPENDIX B, Provision Number 14.5.2.1a, p. 511, add parenthesis to letter “a”:
14.5.2.1(a)
APPENDIX B, Provision Number 18.10.4.4, p. 512, revised as:
8Acvv fc 8Acv fc
APPENDIX B, Provision Number 22.5.1.2, p. 513,
first column revised as:
Vu  (Vc + 0.66 fcbwd )
Vu  (Vc + 0.66 f cbwd )
Second column revised as:
Vu  (Vc + 2.2 f cbwd )
Vu  (Vc + 2.2 fcbwd )
third column, revised as:
Vu  (Vc + 8 fcbwd )
Vu  (Vc + 8 fcbw d )
APPENDIX B, Provision Number 22.7.4.1(a)(b), first column, p. 515, delete repeated part of
equation in next line:
 A2 
f pc
cp 
1+
 pcp 
0.33 f c


Tth < 0.083 f c 
Tth < 0.083
 A2 
f pc
cp 
1+
 pcp 
0.33
 f c


Tth < 0.083 f c 
APPENDIX B, Provision Number 22.7.4.1(a)(c), first column, p. 515, add missing part to the
equation:
 A2 
Nu
cp 
1+
 pcp 
0.33 Ag 


f c 
f c
 A2 
Nu
cp 
1+
 pcp 
0.33
A
g


Tth < 0.083 f c 
f c
INDEX, see Beams, page 517, revised as:
-not participating, 18.14.3