摘要
为了解不同龄期混凝土多次冲击损伤特性,利用大杆径分离式霍金森压杆(SHPB)试验装置对5种不同龄期下的支护混凝土分别进行多次冲击压缩试验,并采用Weibull分布的统计损伤模型分析其损伤特性,系统地了解多次冲击荷载对混凝土造成的损伤规律。结果表明,对每一龄期混凝土,在其临界入射能75%水平的冲击条件下,第一次冲击有助于提高混凝土的抗压强度,之后随着冲击次数增加,混凝土的抗压能力、变形能力都变弱。随着龄期的增长,混凝土损伤-应变曲线表现出2种不同变化形式,损伤度对入射能的敏感度降低,试样失稳时的累积损伤没有明显的变化,均在1.00左右;而峰值损伤则以对数函数关系降低,其中稳定龄期的峰值损伤表明,Weibull分布的统计损伤模型能反映材料的损伤特性。
In order to understand the damage properties of different ages concrete under multiple impact loads systematically,the impact compression tests of 5 early ages concrete were conducted with a large diameter split Hopkinson pressure bar.The damage properties were analyzed by the statistical damage theory based on Weibull distribution to systematically study the damage law of concrete induced by repeated impact loads.The results show that,under the impact condition of 75% critical incident energy,the first time impact could improve the compressive strength of each age concrete.Then,the compressive strength and deformability become weaker with the increasing impact times.The damage-strain curve of concrete displayed different damage properties with the growth of ages.The sensitivity of damage to incident energy decreased.There was no obvious changes of cumulative damage when sample was broken as the age increased,almost at 1.00.However,the peak damage decreased logarithmically as the age increased.Peak damage at stable age indicated that the damage properties can be presented by the statistical damage model based on Weibull distribution.
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2012年第12期2465-2472,共8页
Chinese Journal of Rock Mechanics and Engineering
基金
国家重点基础研究发展计划(973)项目(2010CB732004)
国家自然科学基金资助项目(50934006)
长湘高速公路两型科技示范工程资助项目(CXKJSF0106-2)
