静载和动载下不同龄期混凝土力学特性的试验研究  

EXPERIMENTAL STUDY ON MECHANICAL PROPERTIES OF DIFFERENT AGES CONCRETE UNDER STATIC AND DYNAMIC LOAD

作　　者：王世鸣[1] 李夕兵[1,2] 宫凤强[1,2] 朱晶晶[1] 

机构地区：[1]中南大学资源与安全工程学院,长沙410083 [2]深部金属矿产开发与灾害控制湖南省重点试验室,长沙410083

出　　处：《工程力学》2013年第2期143-149,共7页Engineering Mechanics

基　　金：国家重点基础研究发展计划(973)项目(2010CB732004);长湘高速公路两型科技示范工程项目(CXKJSF0106-2);中南大学中央高校基本科研业务费专项资金项目(2011QNZT090);中南大学研究生学位创新项目(2010ssxt238)

摘　　要：利用杆径为75mm的SHPB试验装置对5种不同龄期下的混凝土分别进行了冲击压缩试验,系统了解了冲击载荷对不同龄期支护混凝土力学特性的影响。为了进行对比,利用INSTRON系统也进行了相应龄期下的静载压缩试验。试验研究表明:静载下混凝土强度、割线弹性模量随龄期增长而增长,其中强度增长主要集中在龄期7d以前,割线弹性模量增长则集中在龄期14d以后,而峰值应变随龄期增长整体上呈减小的趋势;动载下混凝土强度、峰值应变以及单位体积吸收能随着龄期增长而增长,在各个龄期都表现出对应变率具有一定的敏感性,其中不同龄期混凝土的动态强度随应变率增加呈现指数函数增长趋势。不同龄期的混凝土在动载下以拉伸破坏为主,静载下基本呈现剪切破坏形式。In order to understand the mechanical properties of concrete at different ages under dynamic loads systematically, the impact compression tests of 5 early aged concrete were conducted with a 75mm diameter split Hopkinson pressure bar （SHPB）. And static compression tests, for comparison, were also conducted with an INSTRON system. The experimental results show that, although the growth model of concrete strength and elastic modulus under static load are different, both of them increase with the growth of the age, while critical strain decreases with the growth of the age in general; under dynamic loads, the concrete compression strength, critical strain and unit volume absorbed energy increase with the growth of the age, all of them are sensitive to strain rate and the growth trend of concrete dynamic strength with strain rate can be presented with an index function. Under dynamic loads, the concrete is destroyed in a tensile failure mode. And a shear failure mode was presented for concrete under static loads.

关 键 词：混凝土 动态力学性能 霍普金森压杆 不同龄期 应变率 

分 类 号：TU528.1[建筑科学—建筑技术科学]