AGGREGATE TEMPERATURE AND MOISTURE PREDICTION FROM ASPHALT PLANT DATA

A METHOD OF COMBINING MORE THAN 40 AGGREGATE DRYING VARIABLES INTO THREE PRIMARY VARIABLES IS OUTLINED IN THIS REPORT. THE THREE PRIMARY VARIABLES ARE (1) AGGREGATE HEAT ABSORPTION (THE HEATING RATE OF A GIVEN AGGREGATE AT A GIVEN TEMPERATURE DURING DRYING), INCLUDING SECONDARY VARIABLES SUCH AS INITIAL MOISTURE CONTENT, SATURATION, PORE STRUCTURE, AND SOLID THERMAL CHARACTERISTICS, (2) TEMPERATURE GRADIENT (THE EFFECTIVE TEMPERATURE PROFILE OF DRYER GASES FROM ENTRANCE TO EXIT), INCLUDING VARIABLES OF BURNER RATE, FLAME POSITION, AND VEIL DENSITY, AND (3) EXPOSURE TIME (THE TIME A GIVEN AGGREGATE IS EXPOSED TO THE TEMPERATURE GRADIENT), INCLUDING THE VARIABLES OF DRYER SLOPE, LENGTH, ROTATION, AND AGGREGATE SIZE. THE CONTROL OF THESE VARIABLES DURING THE DRYING OPERATION MAKES AGGREGATE TEMPERATURE AT DISCHARGE PREDICTABLE. TO ARRIVE AT THIS FINDING, THE RESULTS OF 250 LABORATORY TESTS ON THREE AGGREGATE TYPES (SIZED 3/4 TO SAND) WERE COUPLED WITH THE CONCLUSIONS OF PREVIOUS AGGREGATE DRYING RESEARCH AT THE OHIO STATE UNIVERSITY. TEMPERATURE AND GRADIENT EXPOSURE TIME HAD BEEN ISOLATED AS SIGNIFICANT VARIABLES IN AGGREGATE DRYING. THE THREE PRIMARY VARIABLES WERE FOUND BY ADDING THE RESULTS OF LAB TESTS ON HEAT ABSORPTION RATES TO DATA FROM PREVIOUS STUDIES. /AUTHOR/

• Record URL:
  http://onlinepubs.trb.org/Onlinepubs/hrbbulletin/358/358-005.pdf
• Supplemental Notes:
  • 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:
  • Lottman, Robert P
• Conference:
  • 41st Annual Meeting of the Highway Research Board
  • Location: Washington DC, United States
  • Date: 1962-1-8 to 1962-1-12
• Publication Date: 1962

Media Info

• Media Type: Digital/other
• Features: Appendices; Figures; References; Tables;
• Pagination: No 358, pp 62-85, 17 FIG
• Monograph Title: Bituminous pavement permeability and field compaction studies on asphaltic concrete
• Serial:
  • Highway Research Board Bulletin
  • Issue Number: 358
  • Publisher: Highway Research Board

Subject/Index Terms

• TRT Terms: Aggregates; Crash exposure; Drying; Flames; Gases; Heating (Structures); Laboratory tests; Location; Methodology; Mixing plants; Moisture content; Percent saturation; Pores; Position fixing; Rotation; Size; Structures; Temperature gradients; Thermal properties; Variables
• Uncontrolled Terms: Data; Exposure; Pores
• Old TRIS Terms: Aggregate drying; Bituminous mixing plants
• Subject Areas: Bridges and other structures; Geotechnology; Highways; Materials; Safety and Human Factors;

Filing Info

• Accession Number: 00210805
• Record Type: Publication
• Files: TRIS, TRB, ATRI
• Created Date: May 13 1994 12:00AM