EFFECTS ON CRACK MEASUREMENT CAUSED BY STEEL REINFORCING BARS

The objectives of the studies presented in this paper were to investigate the effects caused by steel reinforcing bars on determining the depth of cracks which appear on the surface of a concrete structure. Numerical studies were performed to investigate the interaction of stress waves with reinforcing bars. A full scale reinforced concrete beam was constructed as an experimental specimen. The specimen was loaded until cracks occurred. To measure the depth of a crack penetrating into the specimens, two receivers were used and located on thee opposite sides of the crack. The first receiver on the impact side is used to obtain the time of impact initiation. The second receiver located on the other side of the crack is used to trace the arrival of the P-wave diffracted from the bottom edge of the crack. Subsequently, the depth of the crack can be determined. Experimental results show that if tests are performed on the regions without reinforcing bars, the crack depth can be obtained easily because the second receiver initially responds to the arrival of the diffracted P-wave. In the presence of reinforcing bars, the initial disturbance at the second receiver is caused by the arrival of P-wave propagating through reinforcing bars but its amplitude is much smaller than that associated with the following arrival of the P-wave diffracted from the bottom edge of the crack. It is concluded that the presence of reinforcing bars does not make it difficult to measure the crack depth.

• Corporate Authors:

  American Concrete Institute (ACI)

  38800 Country Club Drive
  Farmington Hills, MI  United States  48331
• Authors:
  • Lin, Yun
  • Liou, T
• Conference:
  • High-Performance Concrete: Design and Materials and Recent Advances in Concrete Technology. Proceedings of Third CANMET/ACI International Conference.
  • Location: Kuala Lumpur, Malaysia
  • Date: 1997-0-0 to 1997-0-0
• Publication Date: 1997

Language

• English

Media Info

• Features: Figures; References; Tables;
• Pagination: p. 209-224

Subject/Index Terms

• TRT Terms: Beams; Concrete; Diffraction; Fracture mechanics; Reinforcing bars; Reinforcing steel; Set forward force
• Uncontrolled Terms: Concrete beams
• Subject Areas: Highways; Materials; I32: Concrete;

Filing Info

• Accession Number: 00746550
• Record Type: Publication
• Report/Paper Numbers: SP 172-12
• Files: TRIS
• Created Date: Mar 18 1998 12:00AM