EXPERIMENTAL STUDY ON SPALLING STRENGTH OF CONCRETE

This paper studies the spalling strength of concrete and its strain rate effect, using the large-size (Φ74) Hopkinson pressure bar and relative long concrete specimen bar. The incident compression wave transmitted by the Hopkinson bar into the specimen is reflected as a tensile one causing spalling. Strain gauges are mounted at different points on the specimens and the shape dispersion and attenuation of stress waves traveling through concrete specimens are discussed. The spalling strength is measured with the influence of damage evolvement taken into consideration. The test performed at different strain rates on a kind of common concrete indicates that the spalling strength is substantially influenced by strain rate. It is concluded that the present method for measurement of the spalling strength of concrete is effective.