PROFIS ENGINEERING REPORT TENSION LOAD
Bond Failure Mode
Variables d a
Variables ACI 318-14 Chapter 17 Provision Comments for PROFIS Engineering
d a
17.4.5.1 ………………………….. where
and the constant 1100 carries the unit of lb / in 2 .
c Na
= 10d a т uncr ( 17 . 4 . 5 . 1d ) 1100
17.4.5 . 2 The basic bond strength of a single adhesive anchor in tension in cracked concrete , Nba , shall not exceed
Example :
N ba
= λ a т cr π da h ef
( 17.4.5 . 2 )
Example of a bond strength table in an ICC-ESR showing parameters that are dependent on the anchor element diameter .
ICC-ESR-3187 Table 14
DESIGN INFORMATION Symbol Units
Nominal Rod Diameter ( in ). 3 / 8 1 / 2 5 / 8 3 / 4 7 / 8 1 1-1 / 4
Minimum Embedment h ef , min in 2-3 / 8 2-3 / 4 3-1 / 8 3-1 / 2 3-1 / 2 4 5 ( mm ) 60 70 79 89 89 102 127
Maximum Embedment h ef , max in 7-1 / 2 10 12-1 / 2 15 17-1 / 5 20 25 ( mm ) ( 191 ) ( 254 ) ( 318 ) ( 381 ) ( 445 ) ( 508 ) ( 635 )
Temperature Range A 2
Temperature Range B 2
Temperature Range C 2
Characteristic bond strength psi 1045 1135 1170 1260 1290 1325 1380 in cracked concrete т k , cr ( Mpa ) ( 7.2 ) ( 7.8 ) ( 8.1 ) ( 8.7 ) ( 8.9 ) ( 9.1 ) ( 9.5 )
Characteristic bond strength psi 2220 2220 2220 2220 2220 2220 2220 in uncracked concrete т k , uncr ( Mpa ) ( 15.3 ) ( 15.3 ) ( 15.3 ) ( 15.3 ) ( 15.3 ) ( 15.3 ) ( 15.3 )
Characteristic bond strength psi 1045 1135 1170 1260 1290 1325 1380 in cracked concrete т k , cr ( Mpa ) ( 7.20 ) ( 7.80 ) ( 8.00 ) ( 8.67 ) ( 9.00 ) ( 9.00 ) ( 9.50 )
Characteristic bond strength psi 2220 2220 2220 2220 2220 2220 2220 in uncracked concrete т k , uncr ( Mpa ) ( 15.3 ) ( 15.3 ) ( 15.3 ) ( 15.3 ) ( 15.3 ) ( 15.3 ) ( 15.3 )
Characteristic bond strength psi 855 930 960 1035 1055 1085 1130 in cracked concrete т k , cr ( Mpa ) ( 5.9 ) ( 6.4 ) ( 6.6 ) ( 7.1 ) ( 7.3 ) ( 7.5 ) ( 7.8 )
Characteristic bond strength psi 1820 1820 1820 1820 1820 1820 1820 in uncracked concrete т k , uncr ( Mpa ) ( 12.6 ) ( 12.6 ) ( 12.6 ) ( 12.6 ) ( 12.6 ) ( 12.6 ) ( 12.6 )
Reduction for Seismic Tension α N , seis
- 0.88 1.0 1.0 1.0 1.0 0.97 1.0
1 Bond strength values correspond to concrete compressive strength f ́c = 2500 psi . For concrete compressive strength f ́c between 2500 psi and 800 psi , the tabulated characteristic bond strength may be increased by a factor of ( f ́c / 2500 ) 0 . 1 .
2 Temperature Range A : Maximum short term temperature = 130 ° F , Maximum long term temperature = 110 ° F . Temperature Range B : Maximum short term temperature = 176 ° F , Maximum long term temperature = 110 ° F . Temperature Range C : Maximum short term temperature = 248 ° F , Maximum long term temperature = 162 ° F . Short term elevated concrete temperatures are those which occur over brief intervals , e . g . as a result of diurnal cycling . Long term concrete temperatures are roughly constant over significant periods of time .
The parameter d a is defined in ACI 318-14 Chapter 2 as the “ outside diameter ” of an anchor or the “ shaft diameter ” of a headed stud , headed bolt or hooked bolt . Therefore , d a corresponds to the external diameter of an anchor element . d a is used to calculate the parameter “ c Na ”, which is defined in ACI 318-14 Equation
( 17.4.5.1d ); and the parameter “ N ba
”, which is defined in ACI 318-14 Equation ( 17.4.5.2 ). Other parameters such as effective embedment depth ( h ef
), characteristic bond stress ( т k ) and α N , seis
, which are used in bond strength calculations , are also dependent on the diameter of the anchor element being used .
The PROFIS Engineering adhesive anchor portfolio permits bond strength calculations with the following anchor elements :
• Threaded rods
• Reinforcing bars
• Internally threaded inserts
• Specialty anchor elements
Information about these anchor element types is given in the ICC-ESR for an adhesive anchor system . PROFIS Engineering uses the anchor diameter parameter referenced in the ICC-ESR bond strength tables for an adhesive anchor system to calculate c Na and N ba for a specific anchor element . When design with a threaded rod or reinforcing bar is selected , PROFIS Engineering uses the nominal diameter of the anchor element to calculate c Na and N ba
. When design with Hilti HIS-N and HIS-RN internally threaded inserts is selected , PROFIS Engineering uses the outside diameter of the insert to calculate c Na and N ba . Below are illustrations showing how the parameter d a for calculating c Na and N ba can be defined for various anchor elements . The parameter “ d hole
” noted in the illustrations corresponds to the diameter of the drilled hole into which the adhesive product and anchor element are inserted .
Reference the Variables section of the PROFIS Engineering report for more information on :
h ef
: Effective embedment depth
т k , c , uncr
: Characteristic bond stress in uncracked concrete
т k , c
: Characteristic bond stress in cracked concrete
α N , seis
: Seismic reduction factor
Reference the Calculations section of the PROFIS Engineering report for more information on :
c Na
: Projected distance from an adhesive anchor
N ba
: Basic bond strength for a single adhesive anchor
22 NORTH AMERICAN PROFIS ENGINEERING ANCHORING TO CONCRETE DESIGN GUIDE — ACI 318-14 Provisions