PORTLAND CEMENT CONTENTS REQUIRED TO STABILIZE EASTERN AND WESTERN IOWA LOESS

TESTS WERE CONDUCTED ON IOWA SOIL SERIES SAMPLES TO FIND THE CEMENT CONTENTS REQUIRED TO STABILIZE VARIOUS HORIZONS OF MAJOR UPLAND SOIL SERIES IN TYPICAL LOESS AREAS IN IOWA. A MINIMUM OF TWO SAMPLE LOCATIONS FOR EACH SOIL SERIES WERE INCLUDED AND THE LOCATIONS SELECTED TO SHOW VARIABILITY WITHIN A SOIL SERIES. PATTERNS OF SOIL SERIES IN IOWA ARE TRACED. BASIC SOIL PROPERTY TESTS CONDUCTED WERE MECHANICAL ANALYSIS USING THE HYDROMETER AND PLASTICITY INDEX TEST. SOIL CEMENT TESTS USED TO DETERMINE CEMENT REQUIREMENTS WERE: MOISTURE-DENSITY TESTS, WET-DRY-TESTS, FREEZE-THAW TESTS, AND COMPRESSIVE STRENGTH TESTS. CEMENT REQUIREMENTS OF IOWA LOESS AND LOESSAL SOILS ARE SHOWN TO BE IMPERFECTLY RELATED TO SOIL SERIES DUE TO ERRATIC SUSCEPTIBILITY TO FREEZE-THAW. A THEORY TO EXPLAIN ABNORMAL FREEZE-THAW LOSS IS PROPOSED, AND FREEZE-THAW SENSITIVITY IS CORRELATED TO CLAY CEMENT AND CLAY OCCURRENCE AS COATINGS AND AS AGGREGATES. EXCESSIVE FREEZE-THAW LOSS APPEARS TO BE DUE TO SCALING CAUSED BY VOID SATURATION FROM MOISTURE MOVEMENT OUTWARD IN THE MOLDED CYLINDERS DURING FREEZING. IN ALL AREAS STUDIED, COARSE C HORIZON LOESS WOULD BE THE MOST ECONOMICAL TO STABILIZE. THE CEMENT REQUIREMENT FOR THIS MATERIAL IS USUALLY ABOUT 12%. FINER LOESSES AND B HORIZON MATERIALS OFTEN HAVE REDUCED FREEZE-THAW LOSS DUE TO LOW PERMEABILITY, BUT THE CEMENT REQUIREMENTS ARE USUALLY 14 TO 18 PERCENT. OTHER MATERIALS BECAUSE OF HIGH FREEZE-THAW SENSITIVITY WOULD BE COMPLETELY UNSATISFACTORY FOR SOIL CEMENT, ALTHOUGH WITH SOME OF THESE MATERIALS THE CEMENT REQUIREMENT MAY BE REDUCED BY GREATER COMPACTION. ANOTHER POSSIBLE SOLUTION SUGGESTED BY THE FREEZE-THAW MECHANISM IS TO REDUCE THE FREEZE-THAW SENSITIVITY BY ADMIXING SAND.

  • Supplemental Notes:
    • Joint Publ BULL NO 194 & 23, PP 40-70, 12 FIG, 12 TAB,
  • Corporate Authors:

    Iowa State University, Ames

    2711 South Loop Drive
    Suite 4700
    Ames, IA  United States  50010-8664

    Iowa Engineering Experiment Station

    ,    

    Iowa Department of Transportation

    Iowa Highway Research Board, 800 Lincoln Way
    Ames, IA  United States  50010
  • Authors:
    • Handy, R L
    • Davidson, D T
  • Publication Date: 0

Language

  • English

Subject/Index Terms

Filing Info

  • Accession Number: 00231491
  • Record Type: Publication
  • Files: TRIS, STATEDOT
  • Created Date: Aug 15 2004 2:24AM