EFFECT OF PASTE AGGREGATE BOND STRENGTH ON BEHAVIOR OF CONCRETE

COARSE AGGREGATE WAS COATED WITH A THIN LAYER OF POLYSTYRENE TO REDUCE PASTE-AGGREGATE BOND STRENGTH. THE RESULTING CONCRETE WAS COMPARED TO CONCRETE CONTAINING UNCOATED CONTROL AGGREGATE FOR STRENGTH, STIFFNESS AND TYPE AND AMOUNT OF MICROCRACKING. LARGE CHANGES IN INTER-FACIAL PASTE-AGGREGATE BOND STRENGTH CAUSED ONLY SMALL CHANGES IN COMPRESSIVE STRENGTH, STIFFNESS, AND MICROCRACKING. /JM/