(41CX) Freeze-Thaw Test soil susceptibility

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An extract from A freeze-thaw test to determine the frost susceptibility of soils, USACE-CRREL (FAA & FHWA), AD-A180 000, Special Report 87-1 (94pgs)

ABSTRACT
A new freezing test for determining the frost susceptibility of soils is presented to supplant the standard CRREL freezing test currently specified by the Corps of Engineers. This test reduces the time required to determine the frost susceptibility of a soil in half. It also allows for the determination of both the frost heave and thaw weakening susceptibilities and considers the effects of freeze-thaw cycling. The new freezing test eliminates much of the variability in test results caused by the human element by completely automating the temperature control and data observations.
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1. INTRODUCTION
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In a review of frost susceptibility index testing (Chamberlain 1981), the author concluded that no other available freezing test fulfilled current requirements for performance, efficiency and reliability. A new freezing test was needed, one that would address the deficiencies and draw upon current advances in test automation technology.
This report discusses the current Corps of Engineers practice for conducting freezing tests on soils, describes a new freezing test designed to replace it, outlines in detail test equipment and procedures, and suggests a method of classifying the frost susceptibility of soils based on both frost heave and thaw weakening. A companion report (Chamberlain 1986) discusses the selection process for this new freezing test in greater detail. Details on the automation of the test have also been reported elsewhere (Chamberlain 1984).
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5.2 Data acquisition and control system
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The data acquisition and control unit is controlled with a small, hand-held computer (an HP41CX calculator) … Annotated listings of the programs are provided in Appendix C …
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6.1.3 Calibrating the thermocouples
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… the readings for each T/C will be averaged and stored in the file TSAVE2 in the extended memory of the HP41CX calculator (computer) …
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7.2 Starting the test
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c. The HP41CX calculator will then prompt you for test information as follows:
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APPENDIX C: PROGRAM LISTINGS
C1. Freeze test program
C2. Program to load setup programs
C3. Setup programs
C4. Initial Register storage for the setup programs
C5. Initial flag status for setup programs
C6. Program to determine the thermocouple zero calibrations during initial setup
C7. Subroutine for ALAMAZ
C8. Program to make readings of the displacement transducers during setup
C9. Program to scan the bath temperatures during setup
C1O. Program to initialize the data tape cassette during setup
C11. Program to load running programs
C12. Running programs
C13. Running program register storage
C14. Flag settings
C15. ILOG
C16. TLOG
C17. ALMA
C18. SCAN
C19. Program to control bath temperatures during the freeze-thaw test
C20. Program to reduce the thermocouple data and the DCDT data during the freeze-thaw test
C21. Program to determine the depth of frost penetration during the freeze-thaw test
C22. Program to determine the frost heave and frost penetration rates, frost heave ratio, and segregation potential
C23. Subroutine to determine heave and penetration rates, frost heave ratio, and segregation potential
C24. Program to determine heave rates and penetration rates by regression analysis
C25. Program to print test results and to store results on a tape cassette
C26. Program to summarize test results and shut down the freeze-thaw test
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