DISCUSSION OF REPORT OF COMMITTEE ON STRUCTURAL DESIGN OF ROADS

MR. BREED COMMENTS ON SOME OF THE FACTS ESTABLISHED IN THE PAPERS. IT WAS FOUND THAT A LAYER OF POROUS MATERIAL PLACED OVER A BASE OF POOR SOIL WILL REDUCE THE NUMBER OF CRACKS IN A CONCRETE PAVEMENT. DURING THE EARLY PERIOD OF CURING, WHEN CONCRETE IS LEAST RESISTANT TO STRESS, THE GREATEST CARE SHOULD BE TAKEN TO KEEP IT MOIST AND COVERED. THE DANGER OF RUPTURE FROM CURLING, WHICH IS DUE TO CHANGE OF TEMPERATURE AND TO MOISTURE, IS DIMINISHED BY USE OF THE DIVIDED SLAB. BLOWUPS ARE DUE TO LACK OF ADEQUATE PROVISION FOR EXPANSION. GREATER EXTENSIBILITY OF THE CONCRETE AND OTHER BENEFITS ARE GAINED THROUGH THE USE OF MESH REINFORCEMENT. THINNER BRICK CAN BE USED SUBJECT TO UNIFORM CONTROL TO EFFECT SAVINGS IN FREIGHT AND HANDLING. MR. MCKESSON COMMENTS THAT THE EFFECT OF SUBGRADE TREATMENT IN OHIO IS SIMILAR TO THAT NOTED IN CALIFORNIA. CALIFORNIA FOUND THAT SOIL ADULTERATION WITH CEMENT OR LIME COMPOUND IS NOT AN EFFICIENT OR ECONOMICAL METHOD OF SECURING STABILITY IN HEAVY SOILS. A SAND OR LAYER IS AN EFFICIENT AND ECONOMICAL METHOD OF MINIMIZING DAMAGE TO PAVEMENT RESULTING FROM SWELLING OR SHRINKAGE OF SUBSOIL. MR. CONNELL DESCRIBES THE TYPE OF CROSS SECTION USED IN PENNSYLVANIA. REINFORCEMENT USE IS DISCUSSED. INCREASING THE LAPPING OF REINFORCING TO 12 INCHES HAS CREATED A MARKED DECREASE IN THE NUMBER OF CORNER BREAKS. LAPS ARE BEING OMITTED BETWEEN FABRIC SHEETS AT INTERVALS OF 30, 45, AND 60 FEET ON SECTIONS TO DETERMINE THE CORRECT SPACING FOR PLANES OF WEAKNESS AND TO LOCALIZE THE TRANSVERSE CRACKING. STUDIES ARE CONTINUING OF CALCIUM CHLORIDE AS AN ADMIXTURE FOR CURING CONCRETE PAVEMENTS. THE ACCELERATION IN HARDENING IS BEING STUDIED. EXPERIMENTS ARE BEING CONDUCTED ON USING A THICKENED EDGE TYPE OF BROKEN STONE BASE COURSE OR ONE COURSE BITUMINOUS SURFACE MACADAM ON LIGHT TRAFFIC ROADS WITH THE CROWN OF THE FINISHED SURFACE IN THE SUBGRADE PARABOLIC.

• Record URL:
  https://onlinepubs.trb.org/Onlinepubs/hrbproceedings/6/6-022.pdf
• Supplemental Notes:
  • Vol 6, pp 218-222. 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:
  • Breed, H E
  • Mckesson, C L
  • Connell, W H
• Publication Date: 1927

Media Info

• Media Type: Digital/other
• Monograph Title: Proceedings of the Sixth Annual Meeting of the Highway Research Board Held at Washington, D.C., December 2-3, 1926
• Serial:
  • Highway Research Board Proceedings
  • Volume: 6
  • Publisher: Highway Research Board

Subject/Index Terms

• TRT Terms: Acceleration (Mechanics); Admixtures; Bituminous materials; Calcium chloride; Concrete; Concrete curing; Concrete hardening; Concrete pavements; Cracking; Curling; Economics; Hardness; Humidity; Macadam; Material reinforcement; Pavement layers; Porous materials; Sand; Soil cement; Soil lime mixtures; Soil stabilization; Subgrade (Pavements); Surface treating; Temperature; Transverse cracking
• Uncontrolled Terms: Concrete cracking
• Old TRIS Terms: Bituminous surface treatments; Laps; Subgrade treatments
• Subject Areas: Design; Economics; Geotechnology; Highways; Pavements;

Filing Info

• Accession Number: 00203471
• Record Type: Publication
• Files: TRIS, TRB
• Created Date: Jul 25 1971 12:00AM