1.0 TENSION
1.3 Pullout Failure Mode
Results ϕ concrete
Results ACI 318-19 Chapter 17 Provision Comments for PROFIS Engineering
ϕ concrete
17.5.3 Strength reduction factor ϕ for anchors in concrete shall be in accordance with Tables ……… …….. 17.5.3 ( c )…………………
Table 17.5.3 ( c ) — Anchor strength governed by concrete pullout , or pryout strength
Type of anchor installation
Anchor Category [ 1 ] from ACI 355.2 or ACI 355.4
Tension ( concrete pullout )
Strength reduction factor ϕ
Shear ( concrete pryout )
Cast-in anchors Not applicable 0.70 0.70
Post-installed anchors
1 0.65 2 0.55 3 0.45
Example of a post-installed mechanical anchor strength reduction factor ( ϕ-factor ) corresponding to concrete breakout failure in tension .
ICC-ES ESR-1917 Table 3
DESIGN INFORMATION
Effective min . embedment
Symbol
Units
Strength reduction factor for tension , concrete failure modes , or pullout , Condition B
0.70
Nominal anchor diameter ( in .) 3 / 8 1 / 2 5 / 8 3 / 4 h ef in . 1-1 / 2 2 2-3 / 4 2 3-1 / 4 3-1 / 8 4 3-1 / 4 3-3 / 4 4-3 / 4
0.55 0.65
Example of a post-installed adhesive anchor system strength reduction factor ( ϕ-factor ) corresponding to concrete breakout failure in tension .
ICC-ES ESR-3187 Table 12
DESIGN INFORMATION Symbol Units
Strength reduction factor for tension , concrete failure modes , Condition B
3 / 8 or # 3
1 / 2 or # 4
Nominal Rod Diameter ( in ).
5 / 8 or # 5
3 / 4 or # 6
ϕ - 0.65
7 / 8 or # 7
1 or # 8
# 9
1-14 or # 10
Excerpt from ESR-3187 Table 10 showing the strength reduction factor ( ϕ-factor ) corresponding to pullout failure in tension for HIT-Z / HIT-Z-R threaded rods used with HIT-HY 200 adhesive .
ICC-ES ESR-3187 Table 10
DESIGN INFORMATION Symbol Units
Permissible installation conditions
Dry concrete , water saturated concrete
Anchor Category
Nominal rod diameter ( in .) 3 / 8 1 / 2 5 / 8 3 / 4
- 1 ϕ d ϕ ws
- 0.65
ACI 318-19 strength design provisions treat pullout failure in tension as a “ concrete ” failure mode . The nominal pullout strength ( N pn
) is multiplied by one or more strength reduction factors ( ϕ-factors ) to obtain a design pullout strength ( ϕN pn
). The ϕ-factors given in ACI 318-19 Table 17.5.3 ( c ) are used to calculate the design strength for pullout failure in tension . These ϕ-factors are relevant to static load conditions . An additional strength reduction factor (= 0.75 ) is used to calculate the design strength for pullout failure if the anchorage design is based on seismic load conditions .
PROFIS Engineering designates the ϕ-factor corresponding to “ concrete ” failure modes for static load conditions “ ϕ concrete
”, and applies this ϕ-factor to the nominal pullout strength in tension to obtain a design pullout strength . If seismic load conditions are being modeled , PROFIS Engineering also applies the 0.75 seismic reduction factor to the design pullout strength .
When designing cast-in-place anchors , PROFIS Engineering uses the ϕ-factors given in ACI 318-19 Table 17.5.3 ( c ) to calculate the design pullout strength . The ϕ-factors given in Table 17.5.3 ( c ) for post-installed anchors are only intended to be used as guide values in the absence of product-specific data .
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 . PROFIS Engineering uses the ϕ-factors derived from AC193 / ACI 355.2 or AC308 / ACI 355.4 testing , as given in the ICC-ES evaluation report ( ESR ) for the anchor , to calculate the design pullout strength for the post-installed anchors in its portfolio . Generally speaking , the ϕ-factors that are given in the anchor ESR which used to calculate a design pullout strength for post-installed anchors correspond to the post-installed anchor ϕ-factors given in Table 17.5.3 ( c ).
PROFIS Engineering designates the 0.75 reduction factor noted in ACI 318-19 Section 17.10.5.4 for seismic load conditions “ ϕ seismic
”.
Reference the Equations section of the PROFIS Engineering report for more information on the following parameters :
ϕN pn or ϕN pn , ƒ ́c
: design pullout strength in tension .
Reference the Results section of the PROFIS Engineering report for more information on the following parameter :
ϕ seismic
: strength reduction factor for seismic tension .
98 NORTH AMERICAN PROFIS ENGINEERING ANCHORING TO CONCRETE DESIGN GUIDE — ACI 318-19 Provisions