摘要
超高性能混凝土(ultra-high performance concrete,UHPC)具有超高的强度及出色的耐久性能,然而,UHPC的低水胶比及掺加纤维等因素,使得其流动性能欠佳,进而影响3D打印超高性能混凝土(3D printing of ultra-high performance concrete,3DP-UHPC)在打印过程中的可挤出性能和可建造性能。为了制备适用于高温环境下的3DP-UHPC,本文探究了不同长度、掺量的钢纤维和不同掺量的聚丙烯纤维对3DP-UHPC流变性能、早期力学性能、硬化后力学性能的影响,为后续高温测试提供前期理论依据。结果表明,钢纤维长度是影响可挤出性能的关键因素,钢纤维和聚丙烯纤维的掺量是影响可建造性能的关键因素。随着聚丙烯纤维掺量的增加,湿坯强度逐渐降低,和静态屈服应力发展趋势相同。3D打印工艺约束了钢纤维沿打印方向的定向排列,使打印试块抗折强度较传统浇筑试块提升较高,且孔隙分布呈现差异化特征。
Ultra-high performance concrete(UHPC)exhibits ultra-high strength and exceptional durability.However,the low water-to-binder ratio and fiber incorporation of UHPC lead to a significant reduction in flowability,which adversely affects both the extrudability and buildability of 3D printing of ultra-high performance concrete(3DP-UHPC)during the printing process.In order to prepare 3DP-UHPC suitable for high temperature environment,this paper explored the effects of different lengths and content of steel fiber and different content of polypropylene fiber on the rheological properties,early mechanical properties and mechanical properties after hardening of 3DP-UHPC,which provided a preliminary theoretical basis for subsequent high temperature testing.The results show that the length of steel fiber is the key factor affecting the extrudability,and the content of steel fiber and polypropylene fiber is the key factor affecting the buildability.With the increase of polypropylene fiber content,the wet embryo strength gradually decreases,which is the same as the development trend of static yield stress.The 3D printing process restricts the directional arrangement of steel fibers along the printing direction,so that the flexural strength of the 3D printed test block is higher than that of the traditional poured test block,and the pore distribution shows different characteristics.
作者
赵宇
王哲
朱伶俐
ZHAO Yu;WANG Zhe;ZHU Lingli(School of Civil Engineering,Henan Polytechnic University,Jiaozuo 454003,China;School of Materials Science and Engineering,Henan Polytechnic University,Jiaozuo 454003,China)
出处
《硅酸盐通报》
北大核心
2025年第8期2823-2838,共16页
Bulletin of the Chinese Ceramic Society
基金
河南省科技攻关项目(242102230136,232102320191)。
关键词
3D打印超高性能混凝土
钢纤维
流变性能
湿坯强度
硬化后力学性能
三维孔隙分析
3D printing of ultra-high performance concrete
steel fiber
rheological property
wet embryo strength
mechanical property after hardening
3D porosity analysis
作者简介
赵宇(1981-),男,博士,副教授。主要从事3D打印混凝土方面的研究。E-mail:zhaoyu@hpu.edu.cn;通信作者:朱伶俐,博士,副教授。E-mail:zhull@hpu.edu.cn。
