1.0 TENSION
1.1 Bond Failure Mode
Equations N ag
Equations ACI 318-19 Chapter 17 Provision Comments for PROFIS Engineering
N ag
= A Na ψ ec , Na ψ ed , Na ψ cp , Na
N ba
A Na0
17.6.5.1 Nominal bond strength in tension , …….. N ag of a group of adhesive anchor group satisfying 17.5.1.3.1 shall be calculated ………. by ( b )………..
( b ) For an adhesive anchor group :
N ag
= A Na ψ ec , Na ψ ed , Na ψ cp , Na
N ba
( 17.6.5.1b )
A Na0
ACI 318 anchoring-to-concrete provisions for the nominal bond strength of a group of adhesive anchors ( N ag
) require calculation of various modification factors corresponding to area of influence ( A Na
/ A Na0 ), eccentricity ( ψ ec , Na
), edge distance
( ψ ed , Na ), and splitting ( ψ cp , Na
); and then multiplying these factors by what is termed the “ basic bond strength in tension ” ( N ba
) to obtain a “ nominal bond strength in tension ” ( N ag
).
Reference the Calculations section of the PROFIS Engineering report for more information on the following parameters :
A Na
: area of influence for anchors in tension
A Na0
: area of influence for single anchor in tension
ψ ec , Na
: tension modification factor for eccentricity
ψ ed , Na
: tension modification factor for edge distance
ψ cp , Na
: modification factor for splitting
N ba
: basic bond strength in tension
Reference the Results section of the PROFIS Engineering report for more information on N ag
.
Equations ϕN ag
Equations ACI 318-19 Chapter 17 Provision Comments for PROFIS Engineering
ϕN ag
≥ N ua
17.5 . 2 For each applicable factored load combination , design strength of anchors shall satisfy the criteria in Table 17.5.2 .
Table 17.5.2 Failure Mode Bond Strength of Adhesive Anchor in Tension
Anchors as a Group
ϕN ag
≥ N ua , g
ACI 318-19 strength design provisions for tension check a calculated design strength ( ϕN N
) against a factored tension load ( N ua
). The parameter ϕN ag corresponds to the design bond strength for a group of anchors in tension . The parameter N ua , g corresponds to the factored tension load acting on the anchor group . If ϕN ag ≥ N ua , g for the application being modeled , the provisions of Table 17.5.2 are satisfied for bond failure .
Reference the Results section of the PROFIS Engineering report for more information on the following parameters : Nag : nominal bond strength in tension
ϕ bond
: strength reduction factor for bond failure
ϕ seismic
: strength reduction factor for seismic tension
ϕN ag
: design bond 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 .
10 NORTH AMERICAN PROFIS ENGINEERING ANCHORING TO CONCRETE DESIGN GUIDE — ACI 318-19 Provisions