Table 90 — Suggested embedment , edge distance , and spacing ( see figure below ) to develop 125 % of f y in Grade 60 bars based on ACI 318 Chapter 17 - SDC A and B only 1 , 2 , 3 , 4 , 5 , 6 , 7
Rebar size
Effective embed .
h ef in . ƒ ' c = 2,500 psi ƒ ' c
= 3,000 psi ƒ ' c = 4,000 psi ƒ ' c
= 6,000 psi
Minimum edge dist
c a , min in . Min .
Cond . I
Cond . II spacing
s min in .
Effective embed .
h ef in .
Minimum edge dist
c a , min in . Min .
Cond . I
Cond . II spacing
s min in .
Effective embed .
h ef in .
Minimum edge dist
c a , min in . Min . spacing
s min in .
Effective embed .
h ef in .
Minimum edge dist
c a , min in . Min .
# 3 7 18 8 15 7 18 7 14 7 18 7 13 7 17 6 11 # 4 10 25 11 22 10 25 11 21 9 24 10 19 9 24 9 17 # 5 12 31 15 29 12 31 14 28 12 30 13 25 11 29 11 22 # 6 14 37 19 37 14 36 18 35 14 36 16 32 13 35 14 28 # 7 17 43 23 45 16 42 22 43 16 41 20 39 15 40 17 34 # 8 19 49 27 54 19 49 26 51 18 48 23 47 18 47 21 41 # 9 21 55 32 63 21 54 30 60 20 54 27 54 20 52 24 48 # 10 25 65 37 74 24 62 35 70 23 60 32 64 22 59 28 56
1 For additional information see May-June 2013 issue of the ACI Structural Journal , “ Recommended Procedures for Development and Splicing of Post-Installed Bonded Reinforcing Bars in Concrete Structures ” by Charney , Pal and Silva .
2 h ef is the calculated bar embedment based on uncracked bond and concrete breakout strengths using equations in section 3.1.14 to develop 125 % of nominal bar yield . Additional reductions per ACI 318 , 17.3.1.2 for sustained loading conditions are not included and as such these suggested embedments are not intended for sustained tension load applications . The particular assumptions used for the application of anchor theory to bar development ( e . g ., bar yield and bond strength values ) are a matter of engineering judgment and will in part depend on the specific circumstances of the design . For embedments corresponding to nominal yield ( i . e ., no overstrength ) multiply the unbolded and bolded tabulated hef values by 0.80 and 0.86 , respectively . Reduction factors for non-sustained loading and no bar overstrength may be combined .
3 c a and s are the minimum edge distance and bar spacing ( from bar centerline ) associated with the tabulated embedments . Refer to sec . 3.1.14 for applicability of edge distance “ Condition I ” and “ Condition II .” 4 Applicable for hammer-drilled holes . For rock-drilled and core-drilled holes , contact Hilti . 5 Values determined with bond stresses , k-factors and strength reduction factors taken from ESR-4868 Tables 12 and 13 assuming dry , uncracked concrete conditions where concrete temperatures will not exceed a maximum short-term temperature of 130 ° F ( 55 ° C ) and long-term temperature of 110 ° F ( 43 ° C ). Bond stresses are for static ( non-seismic ) loading conditions . 6 Values are for normal weight concrete . For lightweight concrete contact Hilti . 7 Refer to the Hilti North America Post-Installed Reinforcing Bar Guide for further explanation , background information , and design examples . See Hilti Instructions for Use ( IFU ) for specific installation requirements .
Cond . I
Cond . II
Cond . I
Cond . II spacing
s min in .
≥ c a , min ≥ s min
≥ c a , min
≥ c a , min ≥ s min
( N )
≥ s min h ef
SECTION ( E )
SECTION
PLAN
Illustration of Table 90 dimensions
90 Anchor Fastening Technical Guide Edition 22 | 3.0 ANCHORING SYSTEMS | 3.2.2 HILTI HIT-HY 200 A / R V3 Hilti , Inc . 1-800-879-8000 | en español 1-800-879-5000 | www . hilti . com | Hilti ( Canada ) Corporation | www . hilti . ca | 1-800-363-4458