3D打印钢纤维增强UHPC力学性能试验研究  

Experimental study on mechanical properties of steel fiber reinforced 3D printing UHPC

作　　者：姚一鸣 张珈玮 孙元锋 梁少卿 黎宝山 王景全 鲁聪[1,2,3] YAO Yiming;ZHANG Jiawei;SUN Yuanfeng;LIANG Shaoqing;LI Baoshan;WANG Jingquan;LU Cong(School of Civil Engineering,Southeast University,Nanjing 211189,China;State Key Laboratory of Safety,Durability and Healthy Operation of Long Span Bridges,Nanjing 210096,China;Bridge Engineering Research Center of Southeast University,Nanjing 210096,China;Development and Reform Bureau of Shenzhen Bao’an District,Shenzhen 518100,China;Faculty of Civil Engineering and Mechanics,Jiangsu University,Zhenjiang 212013,China)

机构地区：[1]东南大学土木工程学院,江苏南京211189 [2]长大桥梁安全长寿与健康运维全国重点实验室,江苏南京210096 [3]东南大学桥梁研究中心,江苏南京210096 [4]深圳市宝安区发展和改革局,广东深圳518100 [5]江苏大学土木工程与力学学院,江苏镇江212013

出　　处：《建筑结构学报》2024年第9期29-40,共12页Journal of Building Structures

基　　金：国家自然科学基金项目(52278245,U1934205);中央高校基本科研业务费专项(2242023R40006);中国交通建设集团有限公司院士专项科研经费项目(YSZX-01-2022-02-B)。

摘　　要：为研究3D打印超高性能混凝土(3D printing ultra-high performance concrete,3DP-UHPC)的基本力学性能和破坏模式,制备了钢纤维增强的3DP-UHPC,并进行了抗压、劈裂和抗弯试验,研究钢纤维掺量、受力方向、层间间隔时间对其基本力学性能的影响。结果表明:钢纤维增强的3DP-UHPC具有良好的力学性能,3个方向的抗压强度均能达到160 MPa,最高达200 MPa以上;随着钢纤维掺量提升,3个方向的抗压强度均得到增强;3DP-UHPC存在打印层间薄弱界面,且黏结强度随层间间隔时间增加而明显降低,当层间间隔时间从0 min增加至70 min,层间劈裂强度降低了46.4%;当钢纤维掺量从0.5%增加至2.0%时,抗弯初裂强度提高15.0%,极限强度提高49.4%,抗弯韧性得到提升,开裂模式也从单个贯穿裂缝转变为裂缝偏转、尖端分叉和双缝开裂等模式。To investigate the mechanical properties and failure modes of 3D printed ultra-high performance concrete(3DP-UHPC),steel fiber reinforced 3DP-UHPC was fabricated in this study and experiments including compression,splitting and bending tests were conducted.The effects of steel fiber content,force direction,and inter-layer interval time on the basic mechanical properties were investigated.The 3DP-UHPC specimens show favorable mechanical properties,and the compressive strength in all three loading directions reaches 160 MPa,with the highest strength exceeding 200 MPa.The compressive strengths in all three directions are enhanced as the content of steel fiber increases.The inter-layer bonding strength decreases by 46.4%as the printing interval between adjacent layers increases from 0 min to 70 min.When the steel fiber content increases from 0.5%to 2.0%,the flexural strength at initial cracking increases by 15.0%,and the flexural strength increases by 49.4%.The flexural toughness is also improved.Moreover,the cracking mode changes from single vertical crack to crack deflection,forked cracks at the tip and double major cracks.

关 键 词：超高性能混凝土 3D打印 层间黏结 静力试验 各向异性 破坏模式 

分 类 号：TU528.572[建筑科学—建筑技术科学] TU502.6