Abstract
An analytical scheme is developed for the use of stitches in repairing concrete cracks. The model provides guidelines for selecting the steps, locations and cross-sectional area of the stitches. The proposed model is based on the superposition technique in fracture mechanics in conjunction with a simple pull-out model established in this paper. The proposed fracture model assumes that the final stitch elongation is equal to the final crack mouth opening displacement. The final crack mouth opening displacement is equal to: (1) the external loads opening of the mouth ignoring the stitch's contribution, and (2) the arrest caused by the stitch itself. In this paper, the problem chosen for this purpose is a beam with an edge notch at the center. The beam is subjected to a concentrated load at the mid-span. The analytical solution for a homogeneous beam with edge notch is given in the literature. The predicted results of stitch forces and the critical stress intensity factor are compared to those obtained experimentally.
Résumé
On développe un schéma analytique utilisant des points de suture pour réparer des fissures dans du béton. Ce modèle fournit des directives pour les étapes, la localisation et la superficie transversale des points de suture. Il se base sur la technique de superposition de la mécanique de la rupture en conjonction avec un modèle simple de l'arrachement présenté dans cet article. Le modèle suppose que l'élongation finale de la suture sera égale au déplacement final de l'ouverture de la fissure. Ce déplacement final est égal à (1) l'ouverture de la fissure résultant de la charge externe sans tenir compte de la suture et à (2) l'arrêt résultant de la suture elle-même. Dans cet article, le problème est étudié sur une poutre ayant, au centre, une entaille sur le bord. La poutre est soumise à une charge concentrée au milieu. La solution analytique pour une poutre homogène avec une entaille sur le bord est fournie par la littérature. Les résultats prévus concernant la force des sutures et le facteur d'intensité de la contrainte critique sont comparé à ceux obtenus expérimentalement.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
Abbreviations
- τ:
-
the shear force per unit length
- u:
-
the displacement in the stitch direction
- k1 :
-
a constant
- p:
-
the tensile force in rod
- As :
-
the stitch area
- σ:
-
the normal stress in the stitch
- Es :
-
the Young's modulus of the stitch
- p1 :
-
the force in the stitch at the leg location
- ke :
-
the stiffness of the leg
- u1 :
-
the displacement along the stitch at the leg location
- KI :
-
the mode I stress intensity factor
- w:
-
the crack mouth opening displacement in crack tip zone
- Gc :
-
the concrete shear modulus
- KIC :
-
the critical stress intensity factor
- Kex :
-
the stress intensity factor due to the external loads
- Kclosing :
-
the stitch closing stress intensity factor
- P:
-
the applied force on the beam
- S:
-
the clear span
- b:
-
the depth of the beam
- a:
-
the crack length
References
‘Concrete Repair and Restoration’, ACI Compilation, No. 5, American Concrete Institute, Detroit (1980), 118 (compiled fromConcrete International Design and Construction 2 (9) (Sept. 1980).
Andrews, E. H. and Levy, G. M., ‘Solvent stress crazing in PMMA’,Polymer Surrey15 (1974) 599–607.
Argon, A. S., Hawkins, G. W. and Kuo, H. Y., ‘Reinforcement of Mortar with Metglas Fibers’, Report No 12-75-78 (Department Mechanical Engineering, Massachusetts Institute on Technology, Cambridge, 1978) pp 34.
Barenblatt, G. I., ‘The Mechanical Theory of Equilibrium Cracks in Brittle Fracture: Advanced Applied Mechanics’, V.7 (Academic Press, New York, 1962) 55–129.
Bažant, Z. and Cedolin, L., ‘Fracture mechanics of reinforced concrete’ in ‘Fracture in Concrete’ (American Society of Civil Engineers, New York, 1980) 28–35.
Brown, J.H., ‘Measuring the fracture toughness of cement paste and morter’,Magazine of Concrete Research 24 (81) (Dec. 1972) 185–196.
Dugdale, D.S., ‘Yielding of steel sheets containing slits’,Journal of Mechanics and Physics 8 (1960) 100–104.
Higgins, D. D. and Bailey, J.E., ‘Fracture measurements on cement paste’,Journal of Material Science 11 (1976) 1993–2000.
Lenain, J. C. and Bunsell, A. R., ‘The resistance of crack growth of asbestos cement’,Journal of Material Science 14 (1979) 321–332.
Visalvanich, K. and Naaman, A. E., ‘Fracture methods in cement composites’,Proceedings, ASCE 107 (EM6) (Dec. 1981) 1155–1171.
Visalvanich, K. and Naaman, A. E., ‘Compliance measured fracture toughness of morter and fiber reinforced morter’, in ‘Fracture Mechanics of Ceramics, Rocks, and Concrete’, STP-745 (American Society of Testing and Materials, Philadelphia, 1981) 141–156.
Kitisak, V. and Naaman, A. E., ‘Fracture model for fiber reinforced concrete’,American Concrete Institute (March–April, 1983) 128–138.
Hamoush, S. A. and Salami, M. R., ‘Interfacial strain energy release rate of fiber-reinforced concrete based on bond stress-slip relationship’,American Concrete Institute 87 (6) (Nov.–Dec., 1990) 678–686.
Hamoush, S. A., Terro, M. and Ahmad., S.H., ‘Shear modulus of interfacial bond between fibers and concrete’, Submitted toMagazine of Concrete Research (`995).
Hellan, K. ‘Introduction to Fracture Mechanics’ (McGraw-Hill, 1984).
Jenq, Y.S. and Shah, S.P., ‘Mixed mode fracture of concrete’,International Journal of Fracture (38) (1988) 123–142.
Tada, H. and Paris, P. C., ‘The Stress Analysis of Cracks’, Handbook (Del Research Corporation, Hellertown, Pennsylvania, 1973).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Hamoush, S., Ahmad, S.H. Concrete crack repair by stitches. Mat. Struct. 30, 418–423 (1997). https://doi.org/10.1007/BF02498565
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF02498565