RECORD OF EXPERIMENTAL AIR-ENTRAINED CONCRETE 10 TO 14 YEARS AFTER CONSTRUCTION

THE PERFORMANCE RECORD IS DESCRIBED OF 14 CONCRETE TEST ROADS IN FIVE NORTHEASTERN STATES. BUILT 10 TO 14 YEARS AGO WITH A WIDE RANGE OF VARIABLES, THESE ROADS PROVIDE AN OPPORTUNITY TO COMPARE THE PERFORMANCE OF AIR-ENTRAINED CONCRETE WITH ADJACENT SECTIONS OF THE SAME CONSTRUCTION BUT WITHOUT AIR ENTRAINMENT. HIGH DURABILITY AND ASSURED RESISTANCE TO THE SEVERE EXPOSURE OF REPEATED CYCLES OF FREEZING AND THAWING AND SALT ACTION IN ICE REMOVAL HAVE BEEN GIVEN TO THESE CONCRETE PAVEMENTS OVER A PERIOD OF 10 TO 14 YEARS BY PROPER AIR-ENTRAINMENT IN THE CONCRETE MIXTURE. NO SCALING OR DISINTEGRATION HAS OCCURRED ON ANY OF THE AIR-ENTRAINED CONCRETE SECTIONS OF THE 116 LANE-MILES REPRESENTED. BUT ON MANY ADJACENT SECTIONS WITH CEMENT FROM THE SAME MILL, BUT WITHOUT AIR-ENTRAINMENT, SCALING UP TO 100 PERCENT OF THE AREA HAS OCCURRED. THE USE OF COARSE- GROUND NORMAL CEMENT COMPARED WITH FINE-GROUND CEMENT UNDER THE SAME CONDITIONS HAS NOT IMPROVED THE RESISTANCE TO SCALING AND DISINTEGRATION, BUT WITH AIR-ENTRAINMENT THE PERFORMANCE HAS BEEN OUTSTANDING IN ALL RESPECTS. /AUTHOR/