THE FROST SUSCEPTIBILITY OF SOILS AND ROAD MATERIALS

GROUND TEMPERATURES MEASURED IN BRITAIN DURING FOUR ABNORMALLY COLD WINTERS SINCE 1929 ARE REVIEWED. GENERAL CONCLUSIONS ARE DRAWN RELATING TO THE DEPTH OF FROST PENETRATION AND THE TEMPERATURE CONDITIONS TO WHICH THE SOIL FOUNDATION AND THE VARIOUS LAYERS OF A ROAD PAVEMENT ARE SUBJECTED DURING A SEVERE WINTER. A DESCRIPTION IS GIVEN OF A LABORATORY TEST DEVELOPED AT THE ROAD RESEARCH LABORATORY IN 1945, TO EXAMINE THE FROST-SUSCEPTIBILITY OF ROAD MATERIALS UNDER CONDITIONS OF CONTINUOUS FREEZING. COMPACTED CYLINDRICAL SAMPLES, 4 INCHES IN DIAMETER AND 6 INCHES LONG, ARE FROZEN FROM ONE END WHILE THE OTHER END IS IN CONTACT WITH WATER MAINTAINED AT A TEMPERATURE SLIGHTLY ABOVE FREEZING POINT. THE RESULTING HEAVE IS PLOTTED AGAINST TIME. FROM THE EXPERIENCE GAINED IN RECENT COLD WINTERS, MATERIALS WHICH HEAVE MORE THAN 0.5 TO 0.7 IN AFTER 250 HOURS FREEZING ARE CLASSIFIED AS FROST-SUSCEPTIBLE. RESULTS OF TESTS CARRIED OUT OVER A PERIOD OF 10 TO 15 YEARS ARE CLASSIFIED IN TERMS OF MATERIALS TESTED AS FOLLOWS: COHESIVE SOILS, NON-COHESIVE SOIL, CHALKS, LIMESTONES, GRANITES, BURNT COLLIERY SHALES, SLAGS, AND PULVERIZED FUEL ASHES. CONCLUSIONS RELATING TO THE FROST-SUSCEPTIBILITY OF EACH MATERIAL ARE GIVEN AND WHERE POSSIBLE ARE RELATED TO CLASSIFICATION DATA SUCH AS LIQUID AND PLASTIC LIMITS, PARTICLE SIZE DISTRIBUTION, OR SATURATION MOISTURE CONTENT OF THE AGGREGATE. /AUTHOR/