初始缝高比对钢纤维混凝土断裂性能的影响

硅酸盐通报 ›› 2022, Vol. 41 ›› Issue (10): 3465-3474.

初始缝高比对钢纤维混凝土断裂性能的影响

杨晓华¹, 罗滔², 刘晓剑¹, 叶尔木拉提³

1.中国铁建投资集团有限公司,北京 100085;
2.西京学院陕西省混凝土结构安全与耐久性重点实验室,西安 710123;
3.中铁建新疆京新高速公路有限公司,乌鲁木齐 830022

收稿日期:2022-06-24 修回日期:2022-07-25 出版日期:2022-10-15 发布日期:2022-10-26
通讯作者: 罗滔,博士,副教授。E-mail:luotao19870426@126.com
作者简介:杨晓华(1976—),男,正高级工程师。主要从事道路工程材料方面的研究。E-mail:448715874@qq.com
基金资助:
中铁建投资集团科技研发项目(ZTJ-2021-WBXKYKT);陕西省教育厅专项科研计划项目(19JK0913)

Effect of Initial Notch-to-Depth Ratio on Fracture Properties of Steel Fiber Reinforced Concrete

YANG Xiaohua¹, LUO Tao², LIU Xiaojian¹, YE Ermulati³

1. China Railway Construction Investment Group Co., Ltd., Beijing 100855, China;
2. Shaanxi Key Laboratory of Safety and Durability of Concrete Structures, Xijing Uinversity, Xi'an 710123, China;
3. China Railway Construction G7 Beijing-Urumqi Expressway Co., Ltd., Urumqi 830022, China

Received:2022-06-24 Revised:2022-07-25 Online:2022-10-15 Published:2022-10-26

摘要/Abstract

摘要： 为研究初始缝高比对钢纤维混凝土断裂性能的影响,对三种不同初始缝高比(0.1、0.2、0.3)的钢纤维混凝土开展断裂韧性试验,计算相关的断裂参数,并借助声发射(AE)和数字图像法(DIC)分析了裂缝发展过程中AE能量和全场应变的变化规律。结果表明,钢纤维混凝土的断裂韧性随初始缝高比的增大呈减小趋势,当初始缝高比为0.3时钢纤维混凝土的断裂性能大幅下降。钢纤维混凝土的断裂过程可根据AE能量划分为弹塑性阶段、裂纹稳定扩展阶段和断裂阶段,随初始缝高比增加,弹塑性阶段持续时间减少。DIC分析结果表明,在整个加载过程中,预制裂缝尖端会产生较大的应力集中,裂缝的横向应变较大。研究结果揭示了钢纤维混凝土裂缝发展机理,可为其工程应用提供理论支持。

关键词: 初始缝高比, 钢纤维混凝土, 断裂性能, 声发射, 数字图像法

Abstract: In order to study the effect of the initial notch-to-depth ratio on the fracture properties of steel fiber reinforced concrete, the fracture toughness tests for steel fiber reinforced concrete with different initial notch-to-depth ratios (0.1, 0.2, 0.3) were carried out and the fracture parameters were calculated. By combining acoustic emission (AE) and digital image correlation (DIC) techniques, the variation law of AE energy and full-field strain during fracture development was analyzed. The results show that the fracture toughness of steel fiber reinforced concrete decreases with the increase of the initial notch-to-depth ratio. When the initial notch-to-depth ratio of steel fiber reinforced concrete reaches 0.3, the fracture properties begin to decrease rapidly. The fracture process of steel fiber reinforced concrete is divided into elastic-plastic stage, stable crack propagation stage and fracture stage according to AE energy. With the increase of the initial notch-to-depth ratio, the duration of elastic-plastic stage decreases. The analysis results of DIC show that the prefabricated crack tip produces a large stress concentration and the transverse strain of the crack is large during the whole loading process. The research results reveal the crack development mechanism of steel fiber reinforced concrete, which provides theoretical support for its engineering application.

Key words: initial notch-to-depth ratio, steel fiber reinforced concrete, fracture property, acoustic emission, digital image correlation

中图分类号:

TU528

杨晓华, 罗滔, 刘晓剑, 叶尔木拉提. 初始缝高比对钢纤维混凝土断裂性能的影响[J]. 硅酸盐通报, 2022, 41(10): 3465-3474.

YANG Xiaohua, LUO Tao, LIU Xiaojian, YE Ermulati. Effect of Initial Notch-to-Depth Ratio on Fracture Properties of Steel Fiber Reinforced Concrete[J]. BULLETIN OF THE CHINESE CERAMIC SOCIETY, 2022, 41(10): 3465-3474.

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