FURTHER STUDIES ON FLEXURAL CRACK CONTROL IN STRUCTURAL SLAB SYSTEMS

THIS PAPER IS A CONSOLIDATION OF ALMOST ALL AVAILABLE STUDIES ON THE FLEXURAL CRACKING BEHAVIOR OF TWO-WAY ACTION SLABS AND PLATES. AN ANALYSIS IS MADE OF THE TEST RESULTS OF 90 TWO-WAY ACTION SLABS BOTH RECTANGULAR AND SQUARE AND HAVING VARIOUS BOUNDARY CONDITIONS. LOADS VARIED FROM CONCENTRATED LOAD SIMULATING COLUMN REACTION ON FLAT PLATES, TO UNIFORMLY DISTRIBUTED LOAD. REINFORCEMENT USED VARIED FROM SMOOTH TO DEFORMED WELDED WIRE FABRIC TO REINFORCING BARS. THE CLEAR SPANS OF THE TEST SLABS, THEIR EFFECTIVE DEPTHS, AND THEIR TOTAL THICKNESSES WERE VARIED. A FRACTURE HYPOTHESIS IS PRESENTED AND A GRID INDEX IS PROPOSED AS AN INDICATOR OF THE CONTROLLING FLEXURAL CRACKING PATTERN TO BE EXPECTED AT LOADS UP TO 75-80 PERCENT OF THE ULTIMATE. IT IS SHOWN THAT APART FROM THE REINFORCEMENT STRESS LEVEL THE MAJOR CONTROLLING PARAMETER IS THE SPACING OF THE REINFORCEMENT IN THE TWO ORTHOGONAL DIRECTIONS OF A TWO-WAY ACTION STRUCTURAL SLAB OR PLATE. THE DIAMETER OF THE REINFORCEMENT AND THE CONCRETE COVER WERE THE OTHER PARAMETERS THAT INFLUENCED THE BEHAVIOR OF SLABS, BUT TO A LESSER DEGREE. CRITERIA ARE PROPOSED FOR CRACK CONTROL IN TWO-WAY SLABS, PLATES AND FLAT PLATES OF VARIOUS BOUNDARY CONDITIONS. THE EXTENT OF THE WORK IS SUCH THAT CODIFICATION OF THE RECOMMENDATIONS IS POSSIBLE FOR DIRECT APPLICATION IN CRACK CONTROL DESIGN OF STRUCTURAL SLAB SYSTEMS. /ACI/

  • Authors:
    • Nawy, E G
    • Blair, K W
  • Publication Date: 1972-1

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  • Accession Number: 00209664
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Jul 9 1972 12:00AM