1.0 TENSION
1.3 Pullout Failure Mode
Results ϕ pn
Results ACI 318-19 Chapter 17 Provision Comments for PROFIS Engineering HIT-Z anchor with HIT-HY 200
ϕN pn
17.6.3.1 Nominal pullout strength of a single cast-in anchor , or a single post-installed expansion , screw , or undercut anchor in tension , N pn
, shall be calculated by :
N pn
= ψ c , p
N p
( 17.6.3.1 ) ………………………………………….
17.6.3.2.1 For post-installed expansion , screw or undercut anchors , the values of N p shall be based on the 5 percent fractile of results of tests performed and evaluated according to ACI 355.2 . It is not permissible to calculate the pullout strength in tension for such anchors .
Excerpt from ESR-3187 for Hilti HIT-HY 200 adhesive , referencing provisions for calculating nominal pullout strength in tension ( N pn
) per ACI 318-19 Eq . ( 17.6.3.1 ) with HIT-Z ( carbon steel ) or
HIT-Z-R ( stainless steel ) threaded rods . 4.1.4.1 Static Pullout Strength in Tension : Hilti HIT-Z and HIT-Z-R Anchor Rods :
The nominal static pullout strength of a single anchor in accordance with ACI 318-14 17.4.3.1 and 17.4.3.2 or ACI 318-11 D . 5.3.1 and D . 5.3.2 , as applicable , in cracked and uncracked concrete , N p , cr and N p , uncr
, respectively , is given in Table 10 . For all design cases , ψ c , p = 1.0 .
Excerpt from ESR-3187 Table 10 showing values for N p
, c r , N p , uncr and ϕ-factors derived from testing per AC308 / ACI 355.4 . ICC-ES ESR-3187 Table 10
DESIGN INFORMATION Symbol Units
Temperature Range A
Permissible installation conditions
Pullout strength in cracked concrete
Pullout strength in uncracked concrete
Dry concrete , water saturated concrete
Nominal rod diameter ( in .) 3 / 8 1 / 2 5 / 8 3 / 4
N p , cr lb 7,952 10,936 21,392 27,930
N p , uncr lb 7,952 11,719 21,931 28,460
Anchor Category
- 1 ϕ d ϕ ws
- 0.65
17.5.3 Strength reduction factor ϕ for anchors in concrete shall be in accordance with Tables …… ……….. 17.5.3 ( c )…………………
PROFIS Engineering calculates nominal pullout strength in tension ( N pn
) per ACI 318-19 Eq . ( 17.6.3.1 ). Although not referenced in ACI 318-19 Section 17.6.3.2.1 , pullout failure in lieu of bond failure must be considered for Hilti HIT-HY 200 used with HIT-Z ( carbon steel ) or HIT-Z-R ( stainless steel ) threaded rods . Characteristic pullout strength values derived from testing per the ICC-ES acceptance criteria AC308 in conjunction with the ACI test standard ACI 355.4 are used to calculate a nominal pullout strength ( N pn
) for HIT-HY 200 when used with HIT-Z / Z-R threaded rods . These characteristic values are shown as “ N p , cr
” and “ N p , uncr
” in Table 10 of ESR-3187 . Table 10 also includes ϕ-factors derived from testing per AC308 / ACI 355.4 , which are shown as “ ϕ d
” and “ ϕ ws
”. When modeling static load conditions for HIT-Z / Z-R threaded rods used with HIT-HY 200 , PROFIS Engineering uses the
N p , xxxx
-values andϕ-factors given in Table 10 of ESR-3187 to calculate the design pullout strength .
The ϕ-factors given in the anchor ESR are designated “ ϕ concrete
” in the PROFIS Engineering report . Design pullout strength for static load conditions is designated “ ϕN pn
” in the PROFIS Engineering report , and is calculated as
“ ϕ concrete
N pn
” using the relevant N p , xxxx
-values and ϕ-factors from ESR-3187 Table 10 . If seismic load conditions are being modeled ; PROFIS Engineering applies the additional 0.75 reduction factor to “ ϕ concrete
N pn
” per ACI 318-19 Section 17.10.5.4 , and designates this factor “ ϕ seismic ”. The PROFIS Engineering report parameter
“ ϕN pn ” corresponds to “ ϕ seismic ϕ concrete
N pn
”.
Reference the Equations and Results section of the report for more information on the parameter N pn
.
Reference the Results section of the report for more information on the parameters ϕ concrete and ϕ seismic
.
When modeling mechanical anchors in PROFIS Engineering , Reference the Equations and Results section of the report for information on the pullout parameter ϕN pn , ƒ ́c
.
When modeling cast-in anchors , PROFIS Engineering calculates nominal the pullout strength in tension ( N pn
) per ACI 318-19 Eq . ( 17.6.3.1 ), and the parameter
N p per ACI 318-19 Eq . ( 17.6.3.2.2a ). Reference the cast-in anchor report sections relevant to pullout strength in tension for more information .
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
Strength reduction factor ϕ
Tension ( concrete pullout )
Cast-in anchors |
Not applicable |
0.70 |
|
1 |
0.65 |
Post-installed anchors |
2 |
0.55 |
|
3 |
0.45 |
Shear ( concrete pryout )
0.70
17.10.5.4 The anchor design tensile strength shall be calculated from ( a ) through ( e ) ………………… …………………………………………………………………………………
( c ) 0.75ϕN pn for a single anchor or for the most highly stressed individual anchor in an anchor group
103 NORTH AMERICAN PROFIS ENGINEERING ANCHORING TO CONCRETE DESIGN GUIDE — ACI 318-19 Provisions