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c Na
= 10d a
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т uncr
1100
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17.6.5.1.1 ……… A Na is the projected influence area of a single adhesive anchor or an adhesive anchor group that is approximated as a rectilinear area that projects outward a distance c Na from the centerline of the adhesive anchor , or in the case of an adhesive anchor group , from a line through a row of adjacent adhesive anchors ……..…….
17.6.5.1.2 A Na0 is the projected influence area of a single adhesive anchor with an edge distance of at least Na .
where
A Na0
= ( 2c Na ) 2 ( 17.6.5.1.2a )
c Na
= 10d a т uncr ( 17 . 6 . 5 . 1 . 2b ) 1100
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ACI 318-19 Chapter 17 bond strength calculations are predicated on the parameter “ c Na
”, which is defined in Chapter 2 as the “ projected distance from the center of an anchor shaft on one side of the anchor required to develop the full bond strength of a single adhesive anchor ”. c Na is calculated per Equation ( 17.6.5.1.2b ).
The parameter “ d a
” corresponds to the diameter of the anchor element selected for the PROFIS Engineering application being modeled . The parameter “ т uncr
” corresponds to the characteristic bond stress in uncracked concrete of the adhesive product selected for the PROFIS Engineering application being modeled .
The modification factor A Na accounts for the area of influence assumed to develop with respect to bond failure , for the edge conditions and anchor spacing that have been input into the PROFIS Engineering model . Per the provisions for A Na given in Section 17.6.5.1.1 , PROFIS Engineering limits the geometry used to define A Na to a maximum projected distance from an anchor of c Na .
A Na0 is a modification factor that accounts for the area of influence assumed to develop in concrete , with respect to bond failure , when a tension load is applied to a single anchor without the influence of any fixed edges . Per the provisions for
A Na0 given in Section 17.6.5.1.2 , PROFIS Engineering defines the geometry for A Na0 as a projected distance of “ c Na
” from the anchor in the + x , -x , + y and -y directions .
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Reference the Variables section of the PROFIS Engineering report for more information on the following parameters :
d a
: diameter of anchor element
т uncr
: characteristic bond stress of an adhesive anchor in uncracked concrete
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Reference the Calculations section of the PROFIS Engineering report for more information on the following parameters :
A Na
: area of influence modification factor
A Na0
: idealized area of influence modification factor for a single anchor
c Na
: projected distance from the center of an adhesive anchor
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