PRACTICAL METHOD FOR ENSURING THE SUCCESS OF CRACK AND SEAT OPERATIONS USING THE FALLING WEIGHT DEFLECTOMETER

Cracking and seating (C&S) of rigid pavements before laying asphalt overlays has been extensively used in recent years to control reflective cracks. By inducing small hairline cracks in the portland cement concrete slabs, the potential for reflective cracks is decreased. The performance of the overlayed section highly depends on the cracking pattern developed in the C&S operation. Deflection testing has been used successfully in C&S operations to evaluate the developed cracking pattern. A mechanistic procedure for calibrating the hammer and the roller in C&S operations using falling weight deflectometer (FWD) measurements is presented. This procedure has two phases: (a) determine the hammer parameters (height and spacing) that develop good cracking patterns, full depth cracks with adequate aggregate interlock between the cracked segments and (b) determine the optimum number of passes of a rubber-tired roller. A three-dimensional, dynamic finite element method (3D-DFEM) was used in the analysis to study the effect of crack width and condition on surface deflections. A dynamic loading cycle was used to simulate the FWD loading cycle. Four crack conditions were considered in the analysis: no crack, minor surface cracks, hairline cracks, and wide cracks. A field validation study was conducted to validate the new approach. Four test sections were included in this study. The results of this study are found to be successful. A user-friendly computer program was developed to implement this method. The program can be loaded on the FWD computer. It reads the FWD raw data file and evaluates the cracking pattern. When the desired cracking pattern is achieved, the program searches for the optimum number of passes of the roller.

• Record URL:
  • http://onlinepubs.trb.org/Onlinepubs/trr/1995/1513/1513-007.pdf
• Record URL:
  • https://scholar.google.com/scholar_lookup?title=PRACTICAL+METHOD+FOR+ENSURING+THE+SUCCESS+OF+CRACK+AND+SEAT+OPERATIONS+USING+THE+FALLING+WEIGHT+DEFLECTOMETER&author=S.+Zagloul&author=B.+Coree&author=R.+McDaniel&publication_year=1995
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• Supplemental Notes:
  • This paper appears in Transportation Research Record No. 1513, Flexible Pavement Construction. Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved
• Authors:
  • Zagloul, Sameh M
  • Coree, Brian J
  • McDaniel, Rebecca S
• Publication Date: 1995

Language

• English

Media Info

• Features: Figures; References;
• Pagination: p. 54-60
• Monograph Title: Flexible pavement construction
• Serial:
  • Transportation Research Record
  • Issue Number: 1513
  • Publisher: Transportation Research Board
  • ISSN: 0361-1981

Subject/Index Terms

• TRT Terms: Computer programs; Crack and seat treatment; Cracking; Deflection; Deflection tests; Dynamic loads; Falling weight deflectometers; Field studies; Finite element method; Fracture mechanics; Interlocking aggregates; Mathematical models; Overlays (Pavements); Pavements; Reflection cracking; Rigid pavements; Rollers; Simulation; Test sections; Validation; Width
• Uncontrolled Terms: Crack width; Patterns
• Old TRIS Terms: Passes; Pavement deflection
• Subject Areas: Construction; Highways; Pavements; I52: Construction of Pavements and Surfacings;

Filing Info

• Accession Number: 00715645
• Record Type: Publication
• ISBN: 0309061733
• Files: TRIS, TRB, ATRI
• Created Date: Jan 24 1996 12:00AM