REPORT OF THE TECHNICAL COMMITTEE ON PAVEMENT DESIGN

RESULTS ARE PRESENTED OF A QUESTIONNAIRE CIRCULATED TO ALL PARTIES INTERESTED IN HIGHWAY PAVEMENT DESIGN. THE FOLLOWING CONCLUSIONS ARE DRAWN FROM THE REPLIES RECEIVED: (1) GENERAL ASPECTS OF PAVEMENT THICKNESS FOR COMBINED BASE, BASE COURSE, AND WEARING COURSE APPROXIMATES TO 31 CM AND THE AVERAGE CONCRETE ROAD SLAB IS 23 CM IN THICKNESS. THUS THE VALUE PLACED ON THE EXTRA LOAD CARRYING CAPACITY OF A CONCRETE SLAB IS 8 CM., ASSUMING THAT FOR SOILS OF MODERATE STRENGTH 15 CM OF SUB-BASE IS USED IN ALL CASES, (2) A SWING IS INDICATED TOWARDS USING THE COMMERCIAL VEHICLE AS THE CRITERION, AND (3) WHERE THE SOIL IS SUBJECT TO FROST ATTACK, A TOTAL DEPTH FROM RUNNING SURFACE TO FORMATION VARIES IN THICKNESS FROM 30 TO 150 CM. THE THICKNESS CHOSEN APPEARS TO BE RELATED TO THE PREVELANCE OF FROST AND THE SEVERITY OF ITS EFFECT. THE MOST USUAL CRITERION FOR DETERMINING THE QUALITY OF SUB-BASE MATERIAL ARE GRADING AND THE CBR VALUE. A CONSIDERABLE VARIETY OF METHODS IS USED FOR DETERMINING WHETHER OR NOT THE SUB-BASE MATERIAL IS FROST RESISTANT. IN BITUMINOUS PAVEMENTS THERE IS A DEFINITE TREND TOWARD THE USE OF BASES BOUND WITH TAR, BITUMEN OR CEMENT. ONLY 5 COUNTRIES STILL RELY ON DRY UNBOUND STONE AND 8 COUNTRIES USED WET STONE. THE RANGE OF THICKNESS AND MAXIMUM THICKNESS OF BASE IS MUCH GREATER IN DENMARK THAN IN ANY OF THE OTHER COUNTRIES. THE REASON FOR THIS IS THAT IN DENMARK THE PAVEMENT STRENGTH IS PROVIDED BY THE SURFACING IN BASE ALONE. COATED CHIPPINGS ARE USED TO IMPROVE SKID RESISTANCE. FOR CONCRETE PAVEMENTS MOST OF THE COUNTRIES ACCEPT THAT CONCRETE PAVEMENTS CAN BE CONTINUED RIGHT UP TO BRIDGE DECKS, PRESUMABLY IN THE BELIEF THAT SUFFICIENT ATTENTION IS NOW PAID TO COMPACTION OF EMBANKMENTS TO JUSTIFY THIS. IN GREAT BRITAIN USE OF UNREINFORCED CONCRETE HAS BEEN PERMITTED AS AN ALTERNATIVE FOR TRAFFIC OF UP TO 6,000 COMMERCIAL VEHICLES PER DAY. OPINION ON THE USE OF TRANSVERSE EXPANSION JOINTS IS DIVIDED. THE MAJORITY OF COUNTRIES REQUIRE CONTRACTION JOINTS TO BE DOWELED - 10 AGAINST 4 WHICH DO NOT. ALL COUNTRIES USE A BASE UNDER THE CONCRETE SLAB. IT IS NOW COMMON PRACTICE FOR THIS TO CONSIST OF A MATERIAL BOUND WITH CEMENT OR WITH A BITUMINOUS BINDER. IT IS COMMON PRACTICE TO VARY THE BASE THICKNESS UNDER THE SLAB TO TAKE ACCOUNT OF SUB-GRADE CONDITIONS. THERE IS A FAIR BALANCE BETWEEN SAWING AND WET FORMING IN THE CONSTRUCTION OF BOTH LONGITUDINAL AND TRANSVERSE JOINTS.

• Supplemental Notes:
  • pp 2-19, 2 TAB, 1 APP
• Publication Date: 1967

Media Info

• Serial:
  • Perm Intl Assoc Road Congresses Proc
  • Publisher: Xiiith Congress, Tokyo

Subject/Index Terms

• TRT Terms: Base course (Pavements); Bearing capacity; Binders; Bituminous pavements; California bearing ratio; Chippings; Concrete; Concrete pavements; Contraction joints; Expansion joints; Frost action; Frost susceptibility; Grading (Earthwork); Pavement design; Pavements; Questionnaires; Skid resistance; Slabs; Subbase (Pavements); Thickness; Transverse joints
• Uncontrolled Terms: Grading; Pavement thickness; Subbase
• Old TRIS Terms: Chips; Highway pavement
• Subject Areas: Highways; Pavements;

Filing Info

• Accession Number: 00205550
• Record Type: Publication
• Files: TRIS
• Created Date: May 24 1994 12:00AM