摘要
将不同体积掺量(0%,0.1%,0.2%,0.3%,0.4%,0.5%)的18mm短切玄武岩纤维掺入混凝土中,分别在养护龄期为3d、7d、28d时进行立方体抗压强度、劈裂抗拉强度和抗折强度试验。同时,利用SEM扫描电镜对玄武岩纤维在混凝土中的分布特征进行分析,探究玄武岩纤维掺量对塔里木灌区水工混凝土早期基本力学性能的影响规律。结果表明:1)玄武岩纤维的掺入可明显提高早龄期混凝土的立方体抗压强度、劈裂抗拉强度和抗折强度,且上述强度都随养护龄期的延长而增长,但纤维掺量过大反而对早龄期混凝土的强度增长不利;2)玄武岩纤维对提高早龄期混凝土立方体抗压强度和劈裂抗拉强度的最佳掺量均为0.2%,且相较于0%掺量试件的强度提高幅度分别为23.31%和34.78%;对提高早龄期混凝土抗折强度的最佳掺量为0.4%,相较于0%掺量试件的强度提高幅度为12.62%;3)玄武岩纤维在混凝土裂缝间的桥接作用延缓了裂缝的增长和扩展,纤维表面包裹的水化产物与混凝土基体之间的粘聚性不断增强,是提高早龄期混凝土基本力学性能的主要原因之一。研究成果可为玄武岩纤维混凝土在塔里木灌区实际工程中的应用提供借鉴和参考。
The 18mm chopped basalt fiber with different volume content(0%, 0.1%, 0.2%, 0.3%, 0.4% and 0.5%) were added to concrete and the cube compressive strength tests, splitting tensile strength tests and flexural strength tests were carried out at curing age for 3 days, 7 days and 28 days respectively. Moreover, the distribution characteristics of basalt fiber in concrete were analyzed by Scanning Electron Microscope(SEM), and the influence of basalt fiber content on the basic mechanical properties of early-age hydraulic concrete in Tarim irrigation area was explored. The results show that:1) the addition of basalt fiber could significantly improve cube compressive strength, splitting tensile strength and flexural strength of concrete, and all above increased with the curing age. However, it is harmful to the strength growth of early-age concrete with too many basalts fiber content;2) The optimum basalt fiber content to improve the cube compressive strength and the splitting tensile strength of modified concrete is 0.2%, and the strength improvements compared with unmodified concrete are 23.31% and 34.78% respectively. The optimum basalt fiber content to improve the flexural strength of modified concrete is 0.4%, which increases 12.62% compared with unmodified concrete. 3) The bridging effect of basalt fiber between concrete cracks delays the growth and expansion of cracks. The increasing cohesion between hydration products wrapped on fiber surface and concrete matrix is one of the main reasons to improve the basic mechanical properties of early-age concrete. The research results could provide references for the practical engineering application of basalt fiber concrete in Tarim irrigation area.
作者
王成
李曦彤
葛广华
戎泽斌
李桢怡
薛山
WANG Cheng;LI Xitong;GE Guanghua;RONG Zebin;LI Zhenyi;XUE Shan(College of Water Resources and Architectural Engineering,Tarim University,Alar 843300,China;South Xinjiang Geotechnical Engineering Research Center,Tarim University,Alar 843300,China)
出处
《建筑结构》
CSCD
北大核心
2022年第S02期1037-1042,共6页
Building Structure
基金
新疆生产建设兵团区域创新引导计划项目(2018BB045)
新疆生产建设兵团重点领域科技攻关计划项目(2019AB016)
关键词
玄武岩纤维混凝土
立方体抗压强度
劈裂抗拉强度
抗折强度
微观结构
basalt fiber concrete
cube compressive strength
splitting tensile strength
flexural strength
microstructure
