PROFIS ENGINEERING REPORT TENSION LOAD
Bond Failure Mode
Results ϕ bond
Results ACI 318-14 Chapter 17 Provision Comments for PROFIS Engineering
ϕ bond
17.3.1.1 The design of anchors shall be in accordance with Table 17.3.1.1 . In addition , the design of anchors shall satisfy 17.2.3 for earthquake loading and 17.3.1.2 for adhesive anchors subject to sustained tensile loading .
Table 17.3.1.1 — Required strength of anchors , except as noted in 17.2.3
Failure Mode Single Anchor
Individual anchor in a Group
Steel strength in tension ( 17.4.1 ) ϕN sa ≥ N ua ϕN sa
≥ N ua , i
Concrete breakout strength in tension ( 17.4.2 ) ϕN cb
≥ N ua
Pullout strength in tension ( 17.4.3 ) ϕN pn ≥ N ua ϕN pn
≥ N ua , i
Concrete side-face blowout strength in tension ( 17.4.4 )
Bond strengh of adhesive anchor in tension ( 17.4.5 ) ϕN sb
≥ N ua
ϕN a
≥ N ua
Anchor Group
Anchors as a group
ϕN cbg
≥ N ua , g
ϕN sbg
≥ N ua , g
ϕN ag
≥ N ua , g
17.2.3.4.4 The anchor design tensile strength for resisting earthquake forces shall be determined from consideration of ( a ) through ( e ) for the failure modes given in Table 17.3.1.1 assuming the concrete is cracked unless it can be demonstrated that the concrete remains uncracked :
…………………………………………………………….. ( e ) 0.75ϕN a or 0.75ϕN ag ……………………………………………………………..
17.3.1.2 For the design of adhesive anchors to resist sustained tension loads , in addition to 17.3.1.1 , Eq . ( 17.3.1.2 ) shall be satisfied .
0.55 ϕN ba ≥ N ua , s
( 17.3.1.2 )
Where N ba is determined in accordance with 17.4.5.2 .
ACI 318-14 strength design provisions for bond failure in tension require calculation of a nominal bond strength ( N a or N ag
). The nominal strength is multiplied by one or more strength reduction factors ( ϕ-factors ) to obtain a design strength ( ϕN a or ϕN ag
). ϕ-factors are relevant to static and seismic load conditions . PROFIS Engineering designates the ϕ-factor corresponding to bond failure for static load conditions “ ϕ bond
”.
Adhesive anchor systems can be shown compliance to under the International Building Code via testing per the ICC-ES acceptance criteria AC308 in conjunction with the ACI standard ACI 355.4 . PROFIS Engineering uses the ϕ-factors derived from AC308 / ACI 355.4 testing , as given in the ICC-ESR for the adhesive anchor system , to calculate design bond strength ( ϕN a or ϕN ag
). These ϕ-factors are relevant to the condition of the concrete in the drilled hole into which the adhesive and anchor element are inserted . Possible drilled hole installation conditions include dry , water saturated , water filled , and underwater ( submerged ). Reference the ICC-ESR for ϕ-factors that are specific to these conditions . PROFIS Engineering uses the ϕ-factor corresponding to the drilled hole condition that has been selected to calculate ϕN a or ϕN ag , and designates this parameter “ ϕ bond
” in the Results section of the report .
PROFIS Engineering designates the 0.75 reduction factor noted in ACI 318-14 Section 17.2.3.4.4 for seismic load conditions “ ϕ seismic
”.
The provisions given in ACI 318-14 Section 17.3.1.2 are used to calculate a bond strength ( 0.55ϕN ba
) for a single anchor , which is checked against the highest factored sustained tension load ( N ua , s
) determined to be acting on a single anchor within the anchorage . Equations , variables , calculations and results relevant to this sustained load check are given in the PROFIS Engineering report section titled Sustained Tension Load Bond Strength . PROFIS Engineering uses the ϕ-factor corresponding to the drilled hole condition that has been selected ( dry , water saturated , water filled , submerged ) to calculate 0.55ϕN ba and designates this parameter “ ϕ bond
” in the Results section of the Sustained Tension Load Bond Strength section of the report .
43 NORTH AMERICAN PROFIS ENGINEERING ANCHORING TO CONCRETE DESIGN GUIDE — ACI 318-14 Provisions