Nucleation of microcracks can be detected and analyzed by acoustic emission (AE), by which crack kinematics of locations, types and rientations are quantitatively estimated. The procedure was applied to clarify mechanisms of corrosion cracking. Based on fracture mechanics, numerical analysis was conducted by the boundary element method (BEM). Relations between the stress intensity factors and crack types were investigated by BEM solutions. In experiments, four types of crack patterns were nucleated by employing expansive agent. Following the surface crack, the diagonal crack and/or the horizontal crack propagated. The internal crack extended after the surface crack was terminated. Depending on the crack types, contributions of mode-I and mode-II were varied. According to AE results, four crack patterns observed differently consisted of tensile, mixed-mode and shear cracks. It is demonstrated that mechanisms of corrosion cracking in concrete are dominantly of mode-I failure along with a minor contribution of mixed-mode and mode-II.
[1]
F. Erdogan,et al.
On the Crack Extension in Plates Under Plane Loading and Transverse Shear
,
1963
.
[2]
Alberto Carpinteri,et al.
Mechanical damage and crack growth in concrete
,
1986
.
[3]
M. Ohtsu,et al.
MOMENT TENSOR ANALYSIS OF ACOUSTIC EMISSION FOR CRACKING MECHANISMS IN CONCRETE
,
1998
.
[4]
R. N. L. Smith,et al.
A Boundary Element Method for Curved Crack Problems in Two Dimensions
,
1982
.
[5]
Masayasu Ohtsu,et al.
BEM ANALYSIS OF MIXED-MODE CRACK PROPAGATION DUE TO CORROSION OF REINFORCEMENT IN CONCRETE
,
2002
.
[6]
Masayasu Ohtsu,et al.
Analysis of crack propagation and crackinitiation due to corrosion of reinforcement
,
1997
.
[7]
Masayasu Ohtsu,et al.
Experimental and numerical crack analysis of mixed-mode failure in concrete by acoustic emission and boundary element method
,
1999
.