PART 3 TENSION LOAD
Concrete Breakout Failure Mode
Variables f ́c
Variables ACI 318-14 Chapter 17 Provision Comments for PROFIS Engineering
f ́c
17.2.7 The values of f ́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 . Testing is required for post-installed anchors when used in concrete with f ́c greater than 8000 psi .
17.4.2.2 The basic concrete breakout strength of a single anchor in tension in cracked concrete , N b , shall not exceed
N b
= λ a k c f ́c h ef
1.5
( 17.4.2.2a ) where k c
= 24 for cast-in anchors and 17 for post-installed anchors . The value of k c 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 .
Alternatively , for cast-in headed studs and headed bolts with 11 in . < h ef < 25 in ., N b
, shall not exceed
N b
= 16λ a f ́c h ef
5 / 3
( 17.4.2.2b ) f ́c is a parameter used to define concrete compressive strength . This parameter is used to calculate the “ basic concrete breakout strength in tension ” ( N b
) when calculating the nominal concrete breakout strength in tension ( N cb or N cbg
).
Post-installed mechanical anchors can be shown compliance 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 shown compliance under the International Building Code via testing per the ICC-ES acceptance criteria AC308 in conjunction with the ACI standard ACI 355.4 . f ́c provisions for a specific postinstalled anchor are derived from this testing and will be given in the ICC-ESR for the anchor . PROFIS Engineering uses these f ́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 f ́c-value less than or equal to 8000 psi . Reference the ICC-ESR for f ́c information
specific to a post-installed anchor .
PROFIS Engineering users can input an f ́c-value within the range 2500 psi < f ́c < 8500 psi for post-installed anchor design . The maximum f ́c-value for calculations will be limited to 8000 psi .
PROFIS Engineering users can input an f ́c-value within the range 2500 psi < f ́c < 10,000 psi for cast-in-place anchor design . The maximum f ’ c-value for calculations will be limited to 10,000 psi .
Reference the Equations and Calculations sections of the PROFIS Engineering report for more information on the parameter N b
.
65 NORTH AMERICAN PROFIS ENGINEERING ANCHORING TO CONCRETE DESIGN GUIDE — ACI 318-14 Provisions