早龄期钢纤维混凝土单轴压缩破坏前兆特征  

Failure Precursory Characteristics of Early-Age Steel Fiber Reinforced Concrete under Uniaxial Compression

作　　者：潘晓凤 曹建涛[2] 罗滔 唐丽云[1] PAN Xiaofeng;CAO Jiantao;LUO Tao;TANG Liyun(School of Architecture and Civil Engineering,Xi’an University of Science and Technology,Xi’an 710054,China;School of Energy,Xi’an University of Science and Technology,Xi’an 710054,China;School of Civil Engineering,Xijing University,Xi’an 710123,China)

机构地区：[1]西安科技大学,建筑与土木工程学院,西安710054 [2]西安科技大学,能源学院,西安710054 [3]西京学院,土木工程学院,西安710123

出　　处：《硅酸盐通报》2024年第7期2470-2478,共9页Bulletin of the Chinese Ceramic Society

基　　金：陕西省教育厅专项科研计划项目(19JK0913)。

摘　　要：早龄期混凝土受水化、外荷载等影响,容易产生裂缝,影响结构耐久性,电阻率能较好地反映混凝土内部损伤程度。本研究开展了钢纤维混凝土(SFRC)和普通混凝土(NC)单轴压缩过程中的电阻率监测试验,研究了龄期对SFRC在单轴压缩过程中电阻率变化特性的影响,并在不同龄期对两种混凝土开展了波速测试试验。研究结果表明,龄期对SFRC在单轴压缩过程中的电阻率变化规律影响显著,28 d龄期内,电阻率变化规律依次以“L”型、“V”型和“U”型三种不同的简化模式呈现。试件临近破坏时,电阻率均有所增大,龄期1和3 d时,增长趋势较小,龄期7、14和28 d时,增长显著。电阻率信息反映了混凝土内部裂隙的萌生和发展,可将电阻率的缓慢增大阶段作为SFRC破坏的前兆信息。SFRC的强度和波速均高于NC,且随龄期增长呈增长趋势。Affected by hydration and external load,early-age concrete is prone to crack,which affects the durability of the structure.And the resistivity can better reflect the internal damage degree of concrete.In this study,the resistivity monitoring experiments of steel fiber reinforced concrete(SFRC)and normal concrete(NC)during uniaxial compression were carried out to study the influence of age on the resistivity variation characteristics of SFRC during uniaxial compression.The wave velocity tests of SFRC and NC at different ages were carried out.The findings indicate that the resistivity variation of SFRC during uniaxial compression is significantly influenced by age.Specifically,in the period of 28 d,the resistivity variation patterns exhibit an“L”type,a“V”type,and a“U”type.The resistivity of all specimens increases when specimens approach failure.The rate of increase is minimal at 1 and 3 d,but becomes significant at 7,14,and 28 d.The resistivity data provides insights into the initiation and progression of cracks in concrete,with the gradual increase in resistivity serving as an indicator of impending failure in SFRC.The strength and wave velocity of SFRC are higher than that of NC,and the strength and wave velocity of concrete increase with age.

关 键 词：钢纤维混凝土 早龄期 单轴压缩 电阻率 波速 

分 类 号：TU528[建筑科学—建筑技术科学]