TRACING INITIATION AND PROPAGATION OF CRACKS IN COMPOSITE SLABS

Test results are presented that were derived from studies aimed at determining whether the impact-echo method, a nondestructive test technique based on the use of transient stress waves, can be used to trace the initiation and propagation of cracks in composite slabs subjected to static loads. The number of shear studs in the specimens was designed to satisfy the requirement of the American Institute of Steel Construction Allowable Stress Design (ASD) specifications for full-composite and 80 percent partial-composite structures. Impact-echo tests were conducted at steps with different load levels to trace the initiation and propagation of cracks in the specimens. During the test, the strains of shear studs were measured to confirm the results derived from the impact-echo tests. Investigators found that the key to detecting the formation of a crack in the composite slabs is changes in the impact-echo responses. The location of the crack can be determined by the impact-echo method. Results also reveal that the strains of shear studs start to increase sharply after the applied load corresponding to the presence of cracks. The authors of this paper introduce a new nondestructive technique for detecting cracks in concrete specimens, adding valuable information to experimental results for better interpretation of structural failure mechanism.

Language

  • English

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  • Accession Number: 00728770
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Nov 29 1996 12:00AM