PETROGRAPHIC INVESTIGATIONS OF ROCK DURABILITY AND COMPARISONS OF VARIOUS TEST PROCEDURES

Abstract

TWENTY ROCK SAMPLES WERE EXAMINED AND TESTED IN THE LABORATORY FOR DETERMINING THE QUALITY OF ROCK FOR USE AS RIPRAP. THE SAMPLES WERE PETROGRAPHICALLY EXAMINED, CLASSIFIED ACCORDING TO ROCK TYPE, AND JUDGED FOR PHYSICAL QUALITY. ROUTINE LABORATORY PHYSICAL PROPERTIES TESTS /SPECIFIC GRAVITY, ABSORPTION, LOS ANGELES ABRASION, SODIUM SULFATE SOUNDNESS, AND FREEZE-THAW DURABILITY/ WERE PERFORMED. SEVERAL OTHER TEST PROCEDURES WERE INVESTIGATED WHICH INCLUDE HARDNESS TESTS /SCLEROSCOPE, SCHMIDT IMPACT HAMMER, AND COEFFICIENT OF RESTITUTION BY A PENDULUM IMPACT REBOUND METHOD/, COMPRESSIVE AND TENSILE STRENGTH, ULTRASONIC PULSE VELOCITY, AND A NEWLY DEVELOPED ULTRASONIC ROCK CAVITATION TEST. TEST RESULTS INDICATE NO SINGLE METHOD TO BE CLEARLY SUPERIOR /UNLESS IT BE THE PETROGRAPHIC EXAMINATION/. EACH TEST MEASURES DIFFERENT ROCK PROPERTIES, AND PROVIDES IMPORTANT DATA WHEN EVALUATED IN VIEW OF THE PETROGRAPHIC CHARACTERISTICS OF THE ROCK. THE ULTRASONIC ROCK CAVITATION TEST SHOWS PROMISE AS A GOOD TEST OF ROCK DURABILITY. /AUTHOR/