Issue 69

M. B. Prince et alii, Frattura ed Integrità Strutturale, 69 (2024) 154-180; DOI: 10.3221/IGF-ESIS.69.12

Reference

τ max (SI unit)

Criteria

This equation is valid for pullout failure with

Model Code 2010 [2] (Pullout Failure) Model Code 2010 [2] (Splitting Failure) Model Code 2010 [2] (Splitting Failure with confinement) Sturm and Visintin [3]

c

'

max c τ =2.5 f



5

d

B

f '

This equation is valid for splitting failure without confinement This equation is valid for splitting failure with confinement This equation was proposed for UHPFRC. No limitation of failure pattern was found. The formula was proposed for high-strength concrete with compressive strength equal to or greater than 50 MPa. Moreover, B c 1 d  was another criterion, and most specimens using the regression showed failure due to bond. Pullout failure was dominant in the specimens used to generate this equation. Most of the data on which the empirical equation is based are for B c 2.5 d  Splitting failure mode was the predominant type of failure of the tested specimen The formula was proposed for confined concrete from the partial bond pullout test. The test specimens simulated the behavior of anchored bars with B c =4 d The empirical formula was proposed for confined concrete. The failure pattern was not mentioned explicitly. The empirical formula was proposed for confined concrete. This equation proposed for FRC. d was dominant among the specimens. B c =3.7

c 0.25

max τ =7.0(

)

20

f '

c 0.25

max τ =8.0(

)

20



 '

max c τ = 0.0018c+0.186 f

  

  

B c/d +0.5 c/d +5.5

Esfahani and Rangan [4]

max τ =8.6

f

ct

B

'

Harajli et al. [5]

max c τ =2.57 f

'

Huang et al. [6]

max c τ =0.45f

  

  

c d τ =0.083045 1.2+3 +50

'

B

f

Oragun et al. [7]

c

max

d

l

B

B

' c τ =0.083045 f 22.8-0.208 -38.212 d l       b max c B d d

Hadi [8]

'

f

B d τ =(20- ) max

Soroushian and Choi [9]

c

4 30



   

0.6

B   c     d

B d     B   l

' 0.55

max τ = 0.679 

+3.88

(f c)

Aslani and Samali [10]

 

B 0.7c τ =(0.82+0.9 ) 1.6+ +20 f l d        max SV B B d

Xu [11]

ct

' c 0.0193f

max τ =8.9824e

by simple regression,

The formula was proposed for confined concrete. Both pullout and splitting failures exhibited on the used specimens

by multiple regression, ' c τ =0.384702f -1.73018d -7.40323 +65.90284 d max c B

Tang and Cheng [12]

B

τ max = Maximum bond stress, d B = diameter of pulled reinforcement, l B =bonded length in pullout specimen, c =concrete cover to pulled steel, c / d B = cover to diameter of pulled reinforcement ratio, d S = diameter of confining reinforcement, f c ’ = compressive strength of concrete, f ct = tensile strength of concrete, f y = yield strength of reinforcement, SV  = stirrup ratio Table 1 : Maximum bond stress equation from different literatures and their criteria .

156