基于聚乙烯纤维表面改性的超高性能混凝土应变硬化机理  

Strain-Hardening Mechanism of Ultra-High Performance Concrete Based on Polyethylene Fiber Surface Modification

作　　者：张贵[1] 朋改非[1] 类泽灏 牛旭婧 丁宏 蒋雨恒 范玉春 ZHANG Gui;PENG Gaifei;LEI Zehao;NIU Xujing;DING Hong;JIANG Yuheng;FAN Yuchun(Faculty of Civil Engineering,Beijing Jiaotong University,Beijing 100044,China;Department of Civil Engineering,Trinity College Dublin,The University of Dublin,Dublin D02 PN40,Ireland;School of Mechanics and Civil Engineering,China University of Mining and Technology(Beijing),Beijing 100083,China;Beijing Construction Engineering Group,Advanced Construction Materials Limited Liability Company,Beijing 100015,China;Chinese Academy of Science Key Laboratory of Nanosystem and Hierarchy Fabrication,Chinese Academy of Science Center for Excellence in Nanoscience,National Center for Nanoscience and Technology and University of Chinese Academy of Sciences,Beijing 100190,China;Center for Nanochemistry,Peking University,Beijing 100871,China)

机构地区：[1]北京交通大学土木建筑工程学院,中国北京100044 [2]都柏林大学圣三一学院,土木工程系,爱尔兰都柏林D02PN40 [3]中国矿业大学(北京)力学与建筑工程学院,中国北京100083 [4]北京建工新型建材有限责任公司,中国北京100015 [5]中国科学院大学国家纳米科学中心,中国科学院纳米科学卓越创新中心,中国科学院纳米系统与多级次制造重点实验室,中国北京100190 [6]北京大学纳米化学研究中心,中国北京100871

出　　处：《硅酸盐学报》2021年第11期2346-2354,共9页Journal of The Chinese Ceramic Society

基　　金：北京市自然科学基金项目(8212013,8172036);国家自然科学基金项目(51878032)。

摘　　要：采用不同浓度硅烷偶联剂(SCA)溶液对憎水的聚乙烯纤维(PE纤维)进行表面改性处理,用表面改性后的PE纤维制备超高性能混凝土(UHPC),测定其直拉应变硬化与开裂行为。结果表明:对于低水胶比(0.18)UHPC,掺有3%浓度SCA溶液改性PE纤维得到了较好的应变硬化效果,多缝开裂效果更为显著。改性PE纤维影响UHPC应变硬化的机理是,附着在PE纤维表面的硅烷偶联剂官能团与基体之间建立较强的化学粘结力,其中的自由羟基(—OH)与基体中水化产物C-S-H发生缩合反应,羟基(—OH)与Ca(OH)_(2)中的Ca^(2+)之间发生配位化合作用。Strain-hardening and cracking behavior of UHPC incorporating hydrophobic polyethylene(PE)fibers modified at different concentrations of silane coupling agent(SCA)solution were investigated.The results indicate that for UHPC with a low water binder ratio(0.18),the fiber modified with 3%SCA solution has a better strain-hardening behavior and a more significant multi-cracking behavior.The mechanism for the effect of the surface modification of PE fibers on the strain-hardening of UHPC is due to an effective chemical bonding between the functional groups of SCA attached on the surface of PE fibers and matrix,in which the free hydroxyl group condenses with C-S-H,and the hydroxyl group forms a complexation bond with Ca^(2+) in Ca(OH)_(2).

关 键 词：超高性能混凝土 应变硬化 聚乙烯纤维 表面改性 机理 

分 类 号：TU528[建筑科学—建筑技术科学]