PART 4 SHEAR LOAD
Pryout Failure Mode ( Pryout Bond )
Variables т k , uncr
( continued )
Variables 318-14 Chapter 17 Provision Comments for PROFIS Engineering
т k , uncr
Table 17.4.5.2 — Minimum characteristic bond stresses [ 1 ] [ 2 ]
Installation and service environment
Moisture content of concrete at time of anchor installation
Peak in-service temperature of concrete ° F
Outdoor Dry to fully saturated 175 200 650 Indoor Dry 110 300 1000
[ 1 ] Where anchor design includes sustained tension loading , multiply values of т cr and т uncr by 0.4 . [ 2 ] Where design includes earthquake loads for structures assigned to SDC C , D , E , or F , multiply values of т cr by 0.8 and т uncr by
0.4 .
Example :
Example of a bond strength table in an ICC-ESR showing characteristic bond stress values ( т k , cr and т k , uncr
). ICC-ESR-3187 Table 14
DESIGN INFORMATION Symbol Units т cr psi
Nominal Rod Diameter ( in ). т uncr psi
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 ) ( 191.00 ) ( 254.00 ) ( 318.00 ) ( 381.00 ) ( 445.00 ) ( 508.00 ) ( 635.00 )
Temperature Range A 2
Temperature Range B 2
Temperature Range C 2
Characteristic bond strength in psi 1045 1135 1170 1260 1290 1325 1380 cracked concrete т k , cr ( Mpa ) ( 7.20 ) ( 7.80 ) ( 8.10 ) ( 8.70 ) ( 8.90 ) ( 9.10 ) ( 9.50 )
Characteristic bond strength in psi 2220 2220 2220 2220 2220 2220 2220 uncracked concrete т k , uncr ( Mpa ) ( 15.30 ) ( 15.30 ) ( 15.30 ) ( 15.30 ) ( 15.30 ) ( 15.30 ) ( 15.30 )
Characteristic bond strength in psi 1045 1135 1170 1260 1290 1325 1380 cracked concrete т k , cr ( Mpa ) ( 7.20 ) ( 7.80 ) ( 8.00 ) ( 8.67 ) ( 9.00 ) ( 9.00 ) ( 9.50 )
Characteristic bond strength in psi 2220 2220 2220 2220 2220 2220 2220 uncracked concrete т k , uncr ( Mpa ) ( 15.30 ) ( 15.30 ) ( 15.30 ) ( 15.30 ) ( 15.30 ) ( 15.30 ) ( 15.30 )
Characteristic bond strength in psi 855 930 960 1035 1055 1085 1130 cracked concrete т k , cr ( Mpa ) ( 5.90 ) ( 6.40 ) ( 6.60 ) ( 7.10 ) ( 7.30 ) ( 7.50 ) ( 7.80 )
Characteristic bond strength in psi 1820 1820 1820 1820 1820 1820 1820 uncracked concrete т k , uncr ( Mpa ) ( 12.60 ) ( 12.60 ) ( 12.60 ) ( 12.60 ) ( 12.60 ) ( 12.60 ) ( 12.60 ) т k , uncr
-values in the ICC-ESR are relevant to testing in concrete having a compressive strength of 2500 psi . These values can be increased for compressive strengths 2500 psi < f ́c ≤ 8000 psi using the factor noted in the bond strength table footnotes . PROFIS Engineering increases the т k , uncr
-values by this factor when concrete compressive strengths > 2500 psi are being modeled .
т k , uncr
-values in the ICC-ESR are also dependent on the “ temperature range ” corresponding to “ long term ” and “ short term ” concrete temperatures . The ICC-ESR defines “ long term ” concrete temperatures as being “ roughly constant ” over time . “ Short term ” concrete temperatures are elevated temperatures “ that occur over brief intervals ”. Both types of temperature are relevant to the concrete temperature during the service life of the anchor , not the concrete temperature at the time anchors are installed . Long term and short term temperature ranges are defined in footnotes for the bond strength tables of an adhesive anchor ICC-ESR .
т k , uncr
-values corresponding to a particular temperature range are given in the bond strength table .
Reference the Variables section of the PROFIS Engineering report for more information on :
т k , c
: Characteristic bond stress in cracked concrete
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
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 .
220 NORTH AMERICAN PROFIS ENGINEERING ANCHORING TO CONCRETE DESIGN GUIDE — ACI 318-14 Provisions