Aci 315-99 supersedes aci 315-92 and became effective August 31, 1999

 315-19
DETAILS AND DETAILING OF CONCRETE REINFORCEMENT
American Concrete Institute
P.O. Box 9094
Farmington Hills, Mich. 48333-9094
American Railway Engineering and Maintenance-of-Way
Association 
50 F Street, N.W.
Washington, D.C. 20001
American Society for Testing and Materials 
100 Barr Harbor Drive
West Conshohocken, Pa. 19428
American Society of Civil Engineers
1801 Alexander Bell Drive
Reston, Va. 20191
American Welding Society
550 N.W. LeJeune Road
Miami, Fla. 33126
Association for Information and Image Management
1100 Wayne Avenue, Suite 1100
Silver Springs, Md. 20910
Building Seismic Safety Council
1015 15th Street, N.W., Suite 700
Washington, D.C. 20005
Concrete Reinforcing Steel Institute
933 North Plum Grove Road
Schaumburg, Ill. 60173
International Conference of Building Officials 
5360 South Workman Mill Road
Whittier, Calif. 90601
9.2—Cited references
1. Collins, M. P., and Mitchell, D., “Detailing for Torsion,” ACI 
JOURNAL
,
Proceedings V. 73, No. 9, Sept. 1976, pp. 506-511.
2. Guimaraes, G. N.; Kreger, M. E.; and Jirsa, J. O., “Reinforced Concrete
Frame Connections Constructed Using High-Strength Materials,” University
of Texas at Austin, Aug. 1989 (PMFSEL Report No. 89-1).
CHAPTER 10—NOTATIONS
A
c
= area of core of spirally reinforced compression 
member measured to outside diameter of spiral, 
in.
2
(mm
2
)
A
cv
= net area of concrete section bounded by web
thickness and length of section in the direction of 
shear force considered, in.
2
(mm
2
)
A
g
= gross area of section, in.
2
(mm
2
)
A
s
= area of nonprestressed tension
reinforcement, in.
2
(mm
2
)
b
w
= web width, in. (mm)
c
2
= size of rectangular or equivalent rectangular 
column, capital, or bracket measured transverse 
to the direction of the span for which moments 
are being determined, in. (mm)
d
= distance from extreme compression fiber to 
centroid of tension reinforcement, in. (mm)
d
b
= bar diameter, in. (mm)
f
′
c
= specified compressive strength of concrete, psi (MPa)
f
y
= specified yield strength of nonprestressed 
reinforcement, psi (MPa)
h
= overall thickness of member, in. (mm)
l
d
= development length, in. (mm)
l
dh
= development length for a bar with a standard 
hook, in. (mm)
l
0
= minimum length, measured from joint face along 
axis of structural member, over which transverse 
reinforcement must be provided, in. (mm)
M
u
= factored moment at section
s
= spacing of shear or torsion reinforcement in 
direction parallel to longitudinal reinforcement, 
in. (mm)
s
o
= maximum spacing of transverse reinforcement, 
in. (mm)
ρ
= ratio of nonprestressed tension reinforcement
ρ
v
= A
sv
/A
cv
; where A
sv
is the projection on A
cv
of area 
of distributed shear reinforcement crossing the 
plane of A
cv

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