|
c Na
= 10d a
|
т uncr
1100
|
17.4.5.1 ……… A Na is the projected influence area of a single adhesive anchor or group of adhesive anchors that shall be approximated as a rectilinear area that projects outward a distance c Na from the centerline of the adhesive anchor , or in the case of a group of adhesive anchors , from a line through a row of adjacent adhesive anchors ……..……. A Na0 is the projected influence area of a single adhesive anchor with an edge distance equal to or greater than c Na
.
A Na0
= ( 2c Na ) 2 ( 17.4.5.1c )
|
ACI 318-14 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 ( 17.4.5.1d ).
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 .
|
|
where |
c Na
= 10d a т uncr 17 . 4 . 5 . 1d 1100
|
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 17.4.5.1 , PROFIS Engineering limits the geometry used to define A Na to a maximum projected distance from an anchor of c Na . |
||
and the constant 1100 carries the unit of lb / in 2 . |
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 17.4.5.1 , 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 .
|
|||
|
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
| ||||
|
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
|