STUDY OF THE ANTI-PENETRATION PERFORMANCE OF CONCRETE WITH DIFFERENT COARSE AGGREGATE CONTENT

Abstract

DEEP PENETRATION EXPERIMENTS WERE PERFORMED ON FIVE TYPES OF CONCRETE WITH DIFFERENT COARSE AGGREGATE CONTENT. THE PROJECTILE DIAMETER WAS 29.9 MM, THE INITIAL VELOCITY WAS 647 M/S, AND THE VOLUME FRACTION OF THE COARSE AGGREGATE WAS BETWEEN 0% AND 59.0%. THE DAMAGE LAWS AND DAMAGE MECHANISM OF THE TARGET WERE ANALYZED. THE PURE MORTAR TARGET HAD THE SMALLEST RADIAL CRACK ORIGIN DIAMETER AND CRATER DEPTH. TOO HIGH OF THE COARSE AGGREGATE CONTENT LED TO THE FORMATION OF MANY VOIDS, WHICH LED TO THE DISAPPEARANCE OF RADIAL CRACKS, CRATER SURFACE BYPASSING THE COARSE AGGREGATE AND A LARGE REDUCTION OF CRATER DIAMETER. THE INFLUENCE LAWS AND MECHANISM OF THE COARSE AGGREGATE ON THE PENETRATION DEPTH WERE ALSO ANALYZED. THE INCREASE OF VOLUME FRACTION OF COARSE AGGREGATE WAS BENEFICIAL TO REDUCING PENETRATION DEPTH AND THE INCREASE OF VOIDS VOLUME FRACTION WAS OPPOSITE. THE PENETRATION DEPTH WAS THE LOWEST WHEN THE VOLUME FRACTION OF THE COARSE AGGREGATE REACHED THE MAXIMUM AND NO VOIDS FORMED. BY MODIFYING THE STATIC RESISTANCE STRESS IN THE FORRESTAL PENETRATION FORMULA, A PENETRATION DEPTH MODEL CONSIDERING THE VOLUME FRACTIONS OF THE COARSE AGGREGATE AND VOIDS WAS ESTABLISHED. THE PREDICTED RESULTS WERE IN GOOD AGREEMENT WITH THE EXPERIMENTAL RESULTS.