Accession Number : AD0620930

Title :   DYNAMIC BEHAVIOR OF CONCRETE.

Descriptive Note : Rept. for 4 Mar 64-15 Sep 65,

Corporate Author : CALIFORNIA UNIV BERKELEY

Personal Author(s) : Goldsmith,Werner

Report Date : OCT 1965

Pagination or Media Count : 47

Abstract : Concrete and cement paste specimens, representing a model of the actual structural material and of its adhesive component, respectively, were subjected to static and dynamic tests. Static tests on virgin specimens were carried out in order to evaluate the strength, elasticity and Poisson's ratio of the materials. The dynamic experiments were conducted in order to ascertain the response of the specimens to the propagation of one-dimensional pulse. Transient loading was accomplished by the central longitudinal impact of a 1/2-in diameter steel sphere on a ballisticallysuspended 3/4-in diameter Hopkinson bar of the material at an initial velocity of about 3260 in/sec or 1650 in/sec. The shocked specimens were also subsequently examined to determine whether changes in static material properties had occurred as a result of passage of the waves. Both static and dynamic tests yielded consistent results for a number of specimens cast and cured in identical fashion. Comparison of the properties of the virgin and the shocked specimens indicated little, if any shock damage. While some minor grain damage was observed in microscopic examination of thin sections taken from some of the shocked specimens, other sections did not indicate any visible cracking of the grains. The wave propagation process appeared to occur without dispersion and relatively little attenuation, indicating that the material could be represented on a macroscopic scale as an 'elastic' substance with a small structural damping coefficient. The obvious inhomogenieties of the concrete affected the gage response whenever a gage was mounted directly over a piece of aggregate. (Author)

Descriptors :   (*CONCRETE, DYNAMICS), CEMENTS, LOADS(FORCES), STATICS, COMPRESSIVE PROPERTIES, ELASTIC PROPERTIES, SHOCK RESISTANCE, PROPAGATION, AGING(MATERIALS), TENSILE PROPERTIES

Distribution Statement : APPROVED FOR PUBLIC RELEASE