考虑尺寸及纤维掺量影响的高强混凝土断裂能试验研究  

Experimental Study on Fracture Energy of High Strength Concrete Considering the Influence of Size and Fiber Content

作　　者：徐平[1] 郑满奎 王超[1] 丁亚红[1] 张敏霞[1] 王兴国[1] 马金一 XU Ping;ZHENG Mankui;WANG Chao;DING Yahong;ZHANG Minxia;WANG Xingguo;MA Jinyi(School of Civil Engineering,Henan Polytechnic University,Jiaozuo 454003,China)

机构地区：[1]河南理工大学土木工程学院,焦作454003

出　　处：《硅酸盐通报》2020年第11期3488-3495,共8页Bulletin of the Chinese Ceramic Society

基　　金：河南省科技攻关项目(202102310253);河南省交通运输厅科技项目(2019J-2-13);河南省自然科学基金项目(182300410206,182300410134)。

摘　　要：在断裂能测试分析中,试件尺寸及钢纤维含量同时影响混凝土测试断裂能。为研究不同钢纤维掺量及试件尺寸对高强混凝土断裂能的影响,制备了105根不同钢纤维体积掺量(0%、2%、3%)和缝高比(0.05,0.1,0.15,0.2,0.3,0.4,0.5,0.6,0.7)的几何相似单边切口梁试件。采用三分点加载试验方法,得到了不同开口裂缝深度、试件尺寸大小和钢纤维掺量对高强混凝土断裂能的影响规律。试验结果表明:钢纤维掺量能显著影响高强混凝土断裂能,但随着钢纤维掺量的增加,断裂能增长速度减缓;钢纤维高强混凝土测试断裂能G f随初始裂缝长度的增加呈线性递减,随试件尺寸的增加呈线性递增,表现出明显的尺寸相关性;钢纤维的掺入可削弱试件缝高比变化对测试断裂能的影响,显著提高混凝土的韧性;基于边界影响模型,揭示了初始裂缝长度、试件尺寸对测试断裂能G f产生的影响可归结为试件边界对断裂性过程区的影响。In the fracture energy analysis,the specimen size and steel fiber content affect the fracture energy of concrete.In order to research the effect of steel fiber content and specimen size on the fracture energy of high strength concrete,105 geometrically similar specimens with single-sided notched beams of different steel fiber volume content(0%,2%,3%)and seam height ratio(0.05,0.1,0.15,0.2,0.3,0.4,0.5,0.6,0.7)were prepared.By using the three-point loading test method,the influences of different opening crack depths,specimen size and steel fiber content on the fracture energy of high strength concrete were discussed.The experimental results illustrate that steel fiber content significantly affects the fracture energy of high strength concrete,but with the increasing of steel fiber content,the growth rate of the fracture energy(G f)gradually decreases.G f decreases linearly with the increase of initial crack length and increase linearly with the increase of specimen size,showing an obvious size correlation.The incorporation of steel fibers weakens the impact of variety of seam height ratio on fracture energy and significantly improves the toughness.Based on the boundary effect model,the influence of initial crack length and specimen size on G f are revealed,which can be attributed to the effect of the specimen boundary on the fracture process area.

关 键 词：钢纤维高强混凝土 尺寸相关 三分点加载 断裂能 边界效应 

分 类 号：TU528.572[建筑科学—建筑技术科学]