PART 3 TENSION LOAD
Pullout Failure Mode
Variables α N , seis
Variables ACI 318-14 Chapter 17 Provision Comments for PROFIS Engineering
HIT-Z / HIT-Z-R anchor with HIT-HY 200
α N , seis
17.4.3.1 The nominal pullout strength of a single cast-in , post-installed expansion , and postinstalled undercut anchor in tension , N pn
, shall not exceed
17.4.3 . 2 For post-installed expansion and 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 .
PROFIS Engineering calculates N pn for HIT-Z and HIT-Z-R threaded rods used with HIT-HY 200 adhesive as follows :
N p
, λ a and α Nseis are are shown in the Variables section of the report . ψ c , p is not shown in the report for any post-installed anchor because PROFIS Engineering always sets ψ c , p
= 1.0 for post-installed anchors .
Excerpt from ICC-ESR-3187 for Hilti HIT-HY 200 adhesive , referencing provisions for calculating nominal pullout strength in tension ( N pn
) per ACI 318-14 Eq . ( 17.4.3.1 ) 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 ICC-ESR-3187 Table 10 showing values for N p , cr , N p , uncr and α N , seis derived from testing per AC308 / ACI 355.4 .
ICC-ESR-3187 Table 10
DESIGN INFORMATION Symbol Units
Temperature Range A
Nominal rod diameter ( in .) 3 / 8 1 / 2 5 / 8 3 / 4
Pullout strength in cracked concrete N p , cr lb 7,952 10,936 21,392 27,930
Pullout strength in uncracked concrete N p , uncr lb 7,952 11,719 21,931 28,460
Reduction for seismic tension α N , seis - 0.94 1.0
PROFIS Engineering calculates nominal pullout strength in tension ( N pn
) per ACI 318-14 Eq . ( 17.4.3.1 ). Although not referenced in ACI 318-14 Section 17.4.3.2 , 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 . A characteristic pullout strength in tension ( N p
) derived from testing is used to calculate a nominal pullout strength ( N pn
) for HY 200 when used with HIT-Z / Z-R threaded rods . PROFIS Engineering calculates the nominal pullout strength ( N pn
) for HIT-HY 200 used with HIT-Z or HIT-Z-R threaded rods as follows :
• Determine the relevant N p -value from ICC-ESR-3187 Table 10
• The parameter ψ c , p is set = 1.0
• Calculate a λ a
-value if lightweight concrete conditions are being modeled
• Determine the relevant α N , seis
-value from ICC-ESR-3187 Table 10 if seismic load conditions are being modeled
N p
-values for HIT-Z and HIT-Z-R threaded rods derived from testing per the ICC-ES acceptance criteria AC308 in conjunction with the ACI standard ACI 355.4 are provided in ICC-ESR-3187 Table 10 . PROFIS Engineering uses the N p
-values from ICC-ESR-3187 Table 10 to calculate the nominal pullout strength ( N pn
) for
HIT-Z and HIT-Z-R threaded rods used with HIT-HY 200 adhesive . The parameter ψ c , p in Eq . ( 17.4.3.1 ) is a modification factor for cracked or uncracked concrete . PROFIS Engineering uses ψ c , p
= 1.0 for HIT-HY 200 / HIT-Z / Z-R pullout strength calculations because cracked and uncracked concrete conditions are accounted for in the N p
-values derived from testing . PROFIS Engineering applies a lightweight concrete modification factor ( λ a
) if lightweight concrete conditions are being modeled . The parameter α N , seis is an adhesive anchor modification factor for seismic load conditions . Values for α N , seis are derived from testing per the ICC-ES acceptance criteria AC308 . α N , seis
-values are specific to the adhesive product , the anchor element being used with that product , and the anchor element diameter . Values for α N , seis that are specific to HIT-Z and HIT-Z-R threaded rods used with HIT-HY 200 are given in ICC-ESR-3187 Table 10 .
Reference the Variables section of the report for more information on the following parameters :
• N p
— tested pullout value from ICC-ESR-3187
• λ a
— lightweight concrete modification factor Reference the Results section of the report for more information on the parameter
N pn
.
90 NORTH AMERICAN PROFIS ENGINEERING ANCHORING TO CONCRETE DESIGN GUIDE — ACI 318-14 Provisions