FIFTEEN YEARS OF CEMENT STABILIZED BASES IN GREAT BRITIAN

THE HISTORY OF USE OF CEMENT STABILIZED BASES IN GREAT BRITAIN IS REVIEWED. EXISTING ROADS CONSTRUCTED WITH CEMENT STABILIZED BASES WERE SURVEYED AND FOUND VIRTUALLY FREE FROM CRACKS AND OTHER DEFECTS. ROADS CONSTRUCTED WITH LEAN CONCRETE BASES WERE ALSO SURVEYED AND ONE-THIRD OF THESE SHOWED CRACKS AT LESS THAN 200 FT. INTERVALS, BUT THESE CRACKS DID NOT IMPAIR PERFORMANCE AND SHOW NO SIGN OF DETERIORATION. LEAN CONCRETE DIFFERS FROM OTHER CEMENT STABILIZED MATERIALS IN THAT IT IS MADE FROM GRAVEL OR CRUSHED ROCK PREPARED TO THE STANDARD OF GRADING AND CLEANLINESS REQUIRED FOR CONCRETE AGGREGATES. THE BRITISH STANDARD B.S. 1924 WAS REVISED GIVING NEW METHODS OF TESTING CEMENT STABILIZED MATERIALS. OTHER STANDARD TESTS, PARTICULARLY COMPACTION AND IN SITU DENSITY TESTS, WERE IMPROVED IN DETAIL TO GIVE GREATER RELIABILITY.