纳米增强超高韧性混凝土纤维分布及弯曲性能  

Fiber distribution and flexural properties of nano-reinforced super toughness concrete

作　　者：崔圣爱[1] 张书豪 曾慧姣 詹金科 CUI Sheng’ai;ZHANG Shuhao;ZENG Huijiao;ZHAN Jinke(School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China;CCCC Wuhan Harbor Engineering Design and Research Institute Co.,Ltd.,Wuhan 430040,China)

机构地区：[1]西南交通大学土木工程学院,成都610031 [2]中交武汉港湾工程设计研究院有限公司,武汉430040

出　　处：《东南大学学报(自然科学版)》2025年第1期131-139,共9页Journal of Southeast University:Natural Science Edition

基　　金：成都市科技计划资助项目(2021-YF05-00138-SN);西南交通大学新型交叉学科培育基金资助项目(2682024JX002)。

摘　　要：为探究纳米SiO_(2)掺量与成型工艺对超高韧性混凝土(STC)弯曲性能的影响,制备了4种不同纳米SiO_(2)掺量的STC,通过四点弯曲试验研究了薄层夯捣和常规浇筑2种不同成型工艺下STC的弯曲性能,并结合CT细观测试分析了STC内纤维的取向分布,探讨了弯曲性能与纤维取向之间的关系。结果表明,不同纳米SiO_(2)掺量下,经薄层夯捣的STC弯曲性能相较常规浇筑明显提升;当纳米SiO_(2)掺量为2%时,抗弯强度、初始弯曲韧性比、残余弯曲韧性比分别增加38%、18%、40%。薄层夯倒下纤维分布较为集中,纤维的取向角在40°以内,而常规浇筑下纤维分布较为分散,取向角为20°~80°,说明薄层夯捣有利于纤维的定向分布。所提计算模型准确描述了抗弯强度和纤维取向之间的关系,实测值和计算值的误差小于6%。To study the influence of Nano-SiO_(2)content and molding process on super toughness concrete’s flexural performance,four kinds of super toughness concrete(STC)with different Nano-SiO_(2)contents were prepared.The flexural performance of STC under two different molding processes,thin layer ramming and conventional pouring,was studied through four-point flexural tests.The orientation distribution of fibers in STC was explored by computed tomography(CT)micro-tests.The relationship between the flexural proper-ties and fiber orientation was analyzed.The results show that with different Nano-SiO_(2)contents,the flexural performance of STC by thin layer ramming is superior to that by conventional pouring.When the Nano-SiO_(2)content is 2%,the flexural strength,the initial flexural toughness ratio,and the residual flexural toughness ra-tio are improved by 38%,18%,and 40%.The fiber distribution by thin layer ramming is relatively concen-trated,and the orientation angle of fiber is within 40°,while the distribution of fiber under conventional pour-ing is more scattered,and the orientation angle range is 20°to 80°,indicating that thin layer ramming is condu-cive to the directional distribution of fiber.The proposed calculation model accurately describes the relation-ship between the flexural strength and fiber orientation.The errors between the experimental values and the cal-culated values are less than 6%.

关 键 词：超高韧性混凝土 成型工艺 纳米SiO_(2) 弯曲性能 纤维分布 

分 类 号：TU528[建筑科学—建筑技术科学]