1.0 TENSION
1.3 Pullout Failure Mode
Variables ψ c , P
Variables ACI 318-19 Chapter 17 Provision Comments for PROFIS Engineering
ψ c , P
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 : where ψ c , P is given in 17.6.3.3 . 17.6.3.3 Pullout cracking factor , ψ c , P
N pn
= ψ c , p
N p
( 17.6.3.1 )
17.6.3.3.1 Modification factor to account for the influence of cracking in anchor regions at service load levels , ψ c , P
, shall be determined by ( a ) or ( b ):
( a ) For anchors located in a region of a concrete member where analysis indicates no cracking at service load levels , ψ c , P shall be permitted to be 1.4 .
( b ) For anchors located in a region of a concrete member where analysis indicates cracking at service load levels , ψ c , P shall be taken as 1.0 .
cast-in anchors PROFIS Engineering parameters for calculating the nominal pullout strength of cast-in anchors :
N pn
= ψ c , p
N p
( 17.6.3.1 ) mechanical anchors PROFIS Engineering parameters for calculating the nominal pullout strength of mechanical anchors :
N pn , f ́c
= N p , 2500 λ a
( ƒ ́c / 2500 ) n
ACI 318 anchoring-to-concrete provisions default to an assumption that concrete will crack under service load conditions . ψ c , P is a modification factor for cracked or uncracked concrete conditions when calculating nominal pullout strength in tension . ψ c , P
= 1.0 for cracked concrete conditions . If analysis indicates that concrete will remain uncracked under service load conditions , ψ c , P can be increased to a value of 1.4 .
When designing cast-in anchors with PROFIS Engineering , and cracked concrete conditions are assumed ; PROFIS Engineering calculates the nominal pullout strength ( N pn
) using ψ c , P
= 1.0 . If uncracked concrete conditions are assumed , PROFIS Engineering calculates the nominal pullout strength ( N pn
) using ψ c , P
= 1.4 .
PROFIS Engineering always calculates pullout strength for the post-installed anchors in its portfolio using ψ c , P
= 1.0 , regardless of whether cracked or uncracked concrete conditions have been assumed . When designing mechanical anchors , the nominal pullout strength ( N pn , ƒ ́c
) accounts for cracked or uncracked concrete conditions via the parameter ( N p , 2500
). When designing HIT-Z or HIT-Z-R threaded rods with HIT-HY 200 adhesive , the nominal pullout strength ( N pn
) accounts for cracked or uncracked concrete conditions via the parameter ( N p
).
Reference the Equations and Results section of the cast-in anchor report for more information on the following parameters :
• N pn
— nominal pullout strength for cast-in or adhesive anchors .
Reference the Equations and Results section of the post-installed anchor report for more information on the following parameters :
• N pn
— nominal pullout strength for HIT-Z / R anchors with HIT-HY 200 .
• N pn , ƒ ́c
— nominal pullout strength for mechanical anchors .
Reference the Variables section of the post-installed anchor report for more information on the following parameters :
• N p , 2500 — tested pullout strength for mechanical anchors .
• N p — tested pullout strength for HIT-Z / R anchors with HIT-HY 200 .
HIT-Z / R threaded rods used with HIT-HY 200 adhesive PROFIS Engineering parameters for calculating the nominal pullout strength of HIT-Z and HIT-Z-R threaded rods used with HIT-HY 200 adhesive :
N pn
= N p λ a
86 NORTH AMERICAN PROFIS ENGINEERING ANCHORING TO CONCRETE DESIGN GUIDE — ACI 318-19 Provisions