2.0 SHEAR
2.1 Concrete Breakout Failure Mode
Variables f ́c
Variables ACI 318-19 Chapter 17 Provision Comments for PROFIS Engineering
f ́c
17.3.1 The value of ƒ ́c used for calculation purposes in this chapter shall not exceed 10,000 psi for cast-in anchors , and 8000 psi for post-installed anchors . Post-installed anchors shall not be used in concrete with a strength greater than 8000 psi without testing to verify acceptable performance .
17.7.2 . 2.1 Basic concrete breakout strength of a single anchor in shear in cracked concrete , V b , shall not exceed the lesser of ( a ) and ( b ):
( a ) V b = 7 l e
0.2 d a d λ a
( c a1 ) 1 . 5 ( 17.7.2.2.1a ) a ƒ ́c
……………………………………………………….. ( b ) V b
= 9λ a ƒ ́c ( c a1 ) 1 . 5 ( 17.7.2.2.1b )
17.7.2.2.2 For cast-in headed studs , headed bolts , or hooked bolts that are continuously welded to steel attachments basic concrete breakout strength in shear of a single anchor in cracked concrete , V b
, shall be the lesser of Eq . ( 17.7.2.2.1b ) and Eq . ( 17.7.2.2.2 ) …………………………………….. ƒ ́c is a parameter used to define concrete compressive strength . This parameter is used to calculate the “ basic concrete breakout strength in shear ” ( V b
) when calculating the nominal concrete breakout strength in shear ( V cb or V cbg
).
Post-installed mechanical anchors can be qualified for recognition under the International Building Code via testing per the ICC-ES acceptance criteria AC193 in conjunction with the ACI standard ACI 355.2 . Post-installed adhesive anchor systems can be qualified for recognition under the International Building Code via testing per the ICC-ES acceptance criteria AC308 in conjunction with the ACI standard ACI 355.4 . ƒ ́c provisions for a specific post-installed anchor are derived from this testing and will be given in the ICC-ES evaluation report ( ESR ) for the anchor . PROFIS Engineering uses these ƒ ́c provisions for post-installed anchor design . The post-installed anchor portfolio in PROFIS Engineering is limited to installation in concrete having a specified compressive strength between 2500 psi and 8500 psi , and design using an ƒ ́c-value less than or equal to 8000 psi . Reference the ESR for ƒ ́c information specific to a post-installed anchor .
PROFIS Engineering users can input an ƒ ́c-value within the range 2500 psi ≤ ƒ ́c ≤ 8500 psi for post-installed anchor design . The maximum ƒ ́c-value for calculations will be limited to 8000 psi .
|
V b
= 8
|
l e
0.2
d a
|
d λ a
( c a1 ) 1 . 5 ( 17.5.2.3a ) a ƒ ́c
|
PROFIS Engineering users can input an ƒ ́c-value within the range 2500 psi ≤ ƒ ́c ≤ 10,000 psi for cast-in-place anchor design . The maximum ƒ ́c-value for calculations will be limited to 10,000 psi . |
Excerpt from ESR-3187 ( HIT-HY 200 adhesive anchor system ) showing provisions for f ́c .
5.2 The anchors and post-installed reinforcing bars must be installed in cracked and uncracked normal-weight concrete having a specified compressive strength ƒ ́c = 2500 psi to 8500 psl .
Reference the Equations and Calculations sections of the PROFIS Engineering report for more information on the parameter V b
.
5.3 The values of ƒ ́c used for calculation purposes must not exceed 8000 psi except as noted in Sections 4.2.2 and 4.2.5 of this report .
Excerpt from ESR-1917 ( Kwik Bolt-TZ expansion anchor ) showing provisions for f ́c .
5.2 Anchors must be limited to use in cracked and uncracked normal-weight concrete and lightweight concrete having a specified compressive strength , ƒ ́c of 2500 psi to 8500 psi , and cracked and uncracked normal-weight or sand-lightweight concrete over metal deck having a minimum specified compressive strength , ƒ ́c , of 3000 psi .
5.3 The values of ƒ ́c used for calculation purposes must not exceed 8000 psi .
189 NORTH AMERICAN PROFIS ENGINEERING ANCHORING TO CONCRETE DESIGN GUIDE — ACI 318-19 Provisions