WEST VIRGINIA TEST ROAD - BITUMINOUS MIXTURES STUDIES

TEST ROADS WERE CONSTRUCTED IN WEST VIRGINIA TO PROVIDE FIELD DATA TO SUPPLEMENT LABORATORY STUDIES TO: (1) DEFINE THE EFFECT OF MIXING AND PLACEMENT TEMPERATURES ON THE ENGINEERING PROPERTIES OF ASPHALTIC CONCRETE, AND (2) EVALUATE THE ADEQUACY OF A TENTATIVE DESIGN PROCEDURE FOR HOT-MIXED ASPHALTIC CONCRETE IN WEST VIRGINIA. RELATED STUDIES WERE PERFORMED DURING THE CONSTRUCTION OF THE TEST ROAD TO EVALUATE NUCLEAR DENSITY AND AIR PERMEABILITY CONTROL OF PLACEMENT OF BITUMINOUS MIXTURES, BENKELMAN BEAM DEFLECTIONS BEFORE AND AFTER CONSTRUCTION OF THE SURFACING, AND PRELIMINARY STUDIES OF THE EFFECT OF ROLLER PASSES ON COMPACTION OF HOT-MIXED MATERIAL. THE TEST ROAD CONSTRUCTION AND RESULTS OBTAINED ARE BRIEFLY SUMMARIZED. THE PAVEMENT SECTION CONSISTED OF THE FOLLOWING COURSES: (1) 2-IN EXPERIMENTAL WEARING COURSE, (2) 3/4-IN HOT-LAID ASPHALTIC CONCRETE WEARING COURSE OF LIMESTONE, (3) 2-IN HOT-LAID ASPHALTIC CONCRETE BOTTOM COURSE OF LIMESTONE, AND (4) 16-IN CRUSHED STONE BASE. A TYPICAL COOLING CURVE IS PRESENTED WHICH WAS OBTAINED BY THE THERMOCOUPLE MEASUREMENTS OF THE MIXTURE TEMPERATURE AFTER PLACEMENT AND DURING THE FOLLING OPERATION. THIS CURVE ILLUSTRATES THE TYPICAL INCREASE AND THEN DECREASE IN TEMPERATURE THAT OCCURS AT THE TOP RECORDER AND THE GENERAL DECREASE IN TEMPERATURE THAT OCCURS FOR OTHER LEVELS. THE LOSS OF HEAT AT THE MIXTURE SURFACE AND TO THE BASE APPARENTLY KEEPS THE MIDDLE OF THE MIXTURE AT A HIGHER TEMPERATURE THAN THE TEMPERATURES AT THE TOP AND BOTTOM OF THE LAYER THROUGHOUT THE PERIOD OF OBSERVATION. A GYRATORY TESTING MACHINE FOR COMPATION WAS USED OF THE HOT-MIX TO STIMULATE FIELD COMPACTION. LABORATORY COMPACTION WAS ATTAINED BY THE FIXED-ROLLER EQUIPPED GYRATORY TESTING MACHINE USING A ONE-DEGREE ANGLE OF GYRATION, 100 PSI RAM PRESSURE, AND 30 REVOLUTIONS. TABLES ARE PRESENTED WHICH SHOW THE RESULTS OF CORES TAKEN FROM THE VARIOUS TEST SECTIONS WHICH WERE EVALUATED FOR MEAN DENSITY AND STANDARD DEVIATION. CONTINUOUS OBSERVATION OF THE TEST ROAD PAVEMENT SECTIONS SINCE THEIR CONSTRUCTION APPROXIMATELY THREE YEARS AGO WAS PERFORMED. COMPARISON OF THE AIR FLOW RATE VERSUS AIR CONTENT CURVES FOR THE DIFFERENT MIXTURES SHOWED A CONSIDERABLE VARIATION IN AIR VOID CONTENTS FOR ANY SELECTED FLOWRATE VALUE. IF EXACTING COMPACTION CONTROL IS NOT REQUIRED, IT APPEARS THAT AIR VOID CONTENT MAY BE MAINTAINED WITHIN A RANGE OF 4.0 TO 8.0 PERCENT FOR ALL MIXTURES STUDIED IF A FLOW RATE OF 300 ML./MIN. IS USED AS A FIELD CONTROL CRITERION.

• Supplemental Notes:
  • pp 97-109, 8 FIG, 3 TAB
• Authors:
  • Schaub, J H
  • Ruth, B E
• Publication Date: 1967-11

Media Info

• Serial:
  • Southeast Assoc St Hwy Officials

Subject/Index Terms

• TRT Terms: Air voids; Asphalt concrete; Base course (Pavements); Benkelman beam; Bituminous mixtures; Compaction; Concrete placing; Core samples; Experimental roads; Gyratory testing machines; Hot mix asphalt; Limestone aggregates; Mixing; Nuclear tests; Pavement design; Permeability; Road tests; Rollers; Soil compaction test; Temperature; Test sections; Thermocouples; Wearing course (Pavements)
• Uncontrolled Terms: Laboratory compaction
• Old TRIS Terms: Air voids content; Compaction tests; Cores; Gyratory tests; Mixing temperature; Nuclear moisture density determination; Placing temperature
• Subject Areas: Highways; Materials; Pavements; Vehicles and Equipment;

Filing Info

• Accession Number: 00211412
• Record Type: Publication
• Report/Paper Numbers: pp 109-115
• Files: TRIS
• Created Date: Aug 12 1970 12:00AM