A COMPARISON OF ROAD CONDITIONS WITH ATTERBERG'S LIMITS AND THE OTHER STANDARD SOIL TESTS

COMPARISONS ARE MADE OF VARIOUS SOIL TEST RESULTS TO DETERMINE WHICH TESTS ARE BETTER TO USE IN OHIO. SOILS WERE TESTED WITH ATTERBERG'S LIMITS AND COMPARED WITH OTHER STANDARD SOIL TESTS. THE FOLLOWING TESTS WERE STUDIED: LOWER PLASTIC LIMITS, LOWER LIQUID LIMIT, ATTERBERG NUMBER, MOISTURE EQUIVALENT, VOLUMETRIC CHANGE, SUSPENDED CLAY, AND TOTAL CLAY. THE LOWER LIQUID LIMIT WAS FOUND TO BE THE SAFEST GUIDE OF THE THREE ATTERBERG TESTS. OF THE SEVEN TESTS DISCUSSED, THE LOWER LIQUID LIMIT, THE LOWER PLASTIC LIMIT AND THE VOLUMETRIC CHANGE APPEAR TO CLASSIFY THE SOIL IN THE SAFEST MANNER. IT IS CONCLUDED THAT THERE HAS NOT YET BEEN DEVELOPED A SINGLE SOIL TEST THAT WILL UNERRINGLY DETERMINE WHETHER A PARTICULAR SOIL WILL CAUSE SERIOUS SUBGRADE TROUBLES. ALL SOILS SHOULD BE CONSIDERED WITH SUSPICION WHOSE TESTS SHOW VALUES GREATER THAN 25 FOR THE LOWER LIQUID LIMIT, GREATER THAN 15 FOR THE LOWER PLASTIC LIMIT, GREATER THAN 10 FOR THE ATTERBERG PLASTIC INDEX, GREATER THAN 13 FOR THE VOLUMETRIC CHANGE AND GREATER THAN 18 FOR THE MOISTURE EQUIVALENT. APPARENTLY SOME CHARACTERISTICS OF THE SOIL, SUCH AS THE SHAPE, SIZE OR ROUGHNESS OF THE SOIL GRAIN, IN SOME CASES, HAVE MORE INFLUENCE UPON THE TEST VALUES THAN DOES THE AMOUNT OF THE ULTRA OR TOTAL CLAY.