PROFIS Design Guide - AC 318-19 July 2022 | Page 85

1.3 Pullout Failure Mode

Equations ϕN _pn

Equations ACI 318-19 Chapter 17 Provision Comments for PROFIS Engineering

ϕN _pn

≥ N _ua

17.5 . 2 For each applicable factored load combination , design strength of anchors shall satisfy the criteria in Table 17.5.2 .

Below is a summary of PROFIS Engineering pullout strength calculations . For a single anchor in tension , PROFIS Engineering checks the calculated design strength against the factored tension load acting on that anchor ( N _ua

). For a group of anchors in tension , PROFIS Engineering checks the calculated design strength against the highest factored tension load determined to be acting on a single anchor ( N _ua

). 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 )

PROFIS Engineering parameters for calculating the design pullout strength of cast-in anchors : static load conditions — design strength = ϕ _concrete

N _pn seismic load conditions — design strength = ϕ _seismic ϕ _concrete

N _pn 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

PROFIS Engineering parameters for calculating the design pullout strength of mechanical anchors : static load conditions — design strength = ϕ _concrete

N _{pn , ƒ ́c} seismic load conditions — design strength = ϕ _seismic ϕ _concrete

N _{pn , ƒ ́c}

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 :

ACI 318-19 strength design provisions for tension check a calculated design strength ( ϕN _N

) against a factored tension load ( N _ua

). The parameter “ design strength ” is defined as the product of a “ nominal strength ” ( N _N

) and one or more strength reduction factors ( ϕ-factors ). If ϕN _N ≥ N _ua for all relevant tension failure modes , the ACI 318-19 tension provisions are satisfied .

Nominal pullout strength in tension ( N _pn

) is always calculated for a single anchor when designing with the provisions of ACI 318-19 . If an application consists of a group of anchors in tension , N _pn is calculated for a single anchor , and the design strength is checked against the highest loaded anchor in tension .

Since pullout failure can be considered a “ concrete ” failure mode , PROFIS Engineering designates the strength reduction factor for pullout failure “ ϕ _concrete

”. ACI 318-19 anchoring-to-concrete provisions for seismic load conditions require an additional ϕ-factor to be applied to non-steel design strengths . PROFIS Engineering designates this parameter “ ϕ _seismic

”.

ACI 318-08 anchoring-to-concrete provisions include an additional seismic reduction factor that is applied to anchor design strengths corresponding to brittle failure modes . Pullout failure is considered a brittle failure mode ; therefore , design pullout strengths calculated using ACI 318-08 seismic provisions would include an additional strength reduction factor , which PROFIS Engineering designates “ ϕ _nonductile

”. Since ϕ _nonductile is only relevant to seismic calculations with ACI 318-08 provisions , PROFIS Engineering always shows the parameter “ ϕ _nonductile

” equal to

1.0 in the Results section of reports for ACI 318-19 provisions .

Reference the Equations and Results section of the PROFIS Engineering report for more information on :

N _pn or N _{pn , ƒ ́c}

: nominal pullout strength in tension .

Reference the Results section of the PROFIS Engineering report for more information on the following parameters :

ϕ _concrete

: strength reduction factor for pullout failure

ϕ _seismic

: strength reduction factor for seismic tension ϕN _pn or ϕN _{pn , ƒ ́c}

: design steel strength in tension

N _ua

: factored load acting on anchors in tension

A summary of calculated tension design strength versus the factored tension load for each tension failure mode relevant to the application is given in Part 3 Tension Load of the PROFIS Engineering report .

N _pn

= N _p λ _a

PROFIS Engineering parameters for calculating the design pullout strength of HIT-Z and HIT-Z-R anchors used with HIT-HY 200 adhesive : static load conditions — design strength = ϕ _concrete

N _pn seismic load conditions — design strength = ϕ _seismic ϕ _concrete

N _pn

85 NORTH AMERICAN PROFIS ENGINEERING ANCHORING TO CONCRETE DESIGN GUIDE — ACI 318-19 Provisions