混凝土材料层裂强度的实验研究

利用f74大尺寸Hopkinson压杆和混凝土长杆试件研究了混凝土材料的层裂强度及其应变率效应。入射的压缩波通过压杆透入试件并反射成拉伸波而形成层裂。实验中采取在试件上多点贴应变片,讨论了应力波在混凝土试件中传播的波形弥散和幅值衰减,并在考虑了损伤演化影响的基础上确定了试件材料的层裂强度。对某种普通混凝土在不同应变率下的测试显示层裂强度受应变率影响明显。结果表明,本文提出了一种测定混凝土层裂强度的有效方法。

EXPERIMENTAL STUDY ON SPALLING STRENGTH OF CONCRETE

This paper studies the spalling strength of concrete and its strain rate effect, using the large-size (f74) 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.