| 引用本文: | 王俊颜,喻星乔,周田.掺轻质砂超高性能混凝土的轴拉力学性能[J].哈尔滨工业大学学报,2024,56(2):28.DOI:10.11918/202211080 |
| WANG Junyan,YU Xingqiao,ZHOU Tian.Uniaxial tensile properties of ultra high performance concrete doped with lightweight sand[J].Journal of Harbin Institute of Technology,2024,56(2):28.DOI:10.11918/202211080 |
|
| 摘要: |
| 为研究轻质砂对不同试件尺寸下超高性能混凝土（ultra high performance concrete,UHPC）拉伸应变强化性能的影响,采用轻质砂对原黄砂进行等体积替代,完成9组不同轻质砂体积率（0~35%）和不同试件厚度（30~100 mm）的单轴拉伸试验,并同步进行声发射实时探伤测试。结果表明:轻质砂体积率对UHPC弹性极限点对应应力和对应应变的影响较小,但轻质砂体积率由0增加到35%时,UHPC的极限抗拉强度和极限拉应变分别由10.6 MPa和2.35×10-3提高到了19.4 MPa和4.3×10-3；轻质砂体积率大于15%时,UHPC的应变强化程度得到显著提升,试件内部产生的损伤点数更多且分布更均匀,展现出良好的裂缝控制能力；在相同轻质砂体积率下,UHPC的应变强化程度随试件厚度的增加而降低,且试件内部的损伤点趋于集中,表现出明显的尺寸效应。 |
| 关键词: 轻质砂 超高性能混凝土 拉伸应变强化 声发射 尺寸效应 |
| DOI：10.11918/202211080 |
| 分类号:TU528 |
| 文献标识码:A |
| 基金项目:国家自然科学基金面上项目(52278271);宁波市重大科技专项(2020Z034)；福建省引导性科技计划项目(2022H0028) |
|
| Uniaxial tensile properties of ultra high performance concrete doped with lightweight sand |
|
WANG Junyan1,2,YU Xingqiao1,2,ZHOU Tian1,2
|
|
(1.School of Materials Science and Engineering, Tongji University, Shanghai 201804, China; 2.Key Laboratory of Advanced Civil Engineering Materials (Tongji University), Ministry of Education, Shanghai 201804, China)
|
| Abstract: |
| To explore the effects of lightweight sand on the strain hardening properties of ultra high performance concrete (UHPC) with different specimen sizes, the lightweight sand was used to replace the yellow sand by equal volume. Nine groups of uniaxial tensile tests were carried out with different lightweight sand volume rate ranging from 0 to 35% and different specimen thicknesses from 30 mm to 100 mm. Meanwhile, simultaneous acoustic emission real-time flaw detection tests were conducted. Results show that the volume rate of lightweight sand demonstrates little effect on the stress and strain at the elastic limit point of UHPC, but when the volume rate of lightweight sand increases from 0 to 35%, the ultimate tensile strength and ultimate tensile strain of UHPC grow from 10.6 MPa and 2.35×10-3 to 19.4 MPa and 4.3×10-3 respectively. When the volume rate of lightweight sand is greater than 15%, the strain hardening degree of UHPC significantly increase with more damage points generated and more uniformly distributed inside the specimen, showing remarkable crack control capability. With the same lightweight sand volume rate, the strain hardening degree of UHPC decreases with the increase of specimen thickness, and the damage points inside the specimen tend to be concentrated, exhibiting an obvious size effect. |
| Key words: lightweight sand ultra high performance concrete tensile strain hardening acoustic emission size effect |
