湿度变化对交替3D打印试件微结构及力学性能的影响研究  

Effect of Humidity Evolution on Microstructure and Mechanical Properties of Alternate 3D Printing Specimens

作　　者：曹乾菲 崔冬 史晓晗 万逸 左晓宝[1] 赖建中[3] CAO Qianfei;CUI Dong;SHI Xiaohan;WAN Yi;ZUO Xiaobao;LAI Jianzhong(School of Science,Nanjing University of Science and Technology,Nanjing 210094,China;Department of Physics,Peking University,Beijing 100871,China;Department of Materials Science and Engineering,Nanjing University of Science and Technology,Nanjing 210094,China)

机构地区：[1]南京理工大学理学院,南京210094 [2]北京大学物理学院,北京100871 [3]南京理工大学材料科学与工程学院,南京210094

出　　处：《硅酸盐通报》2021年第6期1879-1888,共10页Bulletin of the Chinese Ceramic Society

基　　金：国家自然科学基金(52008210,12004182);江苏省高性能土木工程材料重点实验室开放基金(1193171134959);南京理工大学自主科研专项基金(30920021146);江苏省自然科学基金青年项目(BK20200481)。

摘　　要：本文提出一种全新的硅酸盐水泥(PC)与碱激发矿渣(AAS)交替3D打印工艺,并基于该工艺打印了硅酸盐水泥-碱激发矿渣复合试件。在试件干燥前后,分别采用X射线断层扫描成像技术(CT)分析了各复合试件以及碱激发矿渣打印试件的微观结构,并测试了各试件干燥前后的抗折与抗压强度。结果表明,碱激发矿渣与硅酸盐水泥的抗干缩性能不同,在内部湿度下降时,两种材料的打印界面容易因干缩不一致而开裂,引起打印成品微结构劣化以及力学性能下降。尽管如此,采用交替3D打印工艺,硅酸盐水泥有效弥补了碱激发矿渣强度的不足,打印成品的抗折与抗压强度均高于碱激发矿渣打印试件。对比逐层交替与逐列交替两种3D打印方法,逐层打印试件的抗折强度更高,而逐列打印试件的抗压强度更高。上述研究成果对3D打印混凝土技术的推广运用有一定指导意义。This paper offers a novel alternate 3D printing technique using alkali-activated slag(AAS)and Portland cement(PC),based on which AAS-PC composite specimens were prepared.The microstructures of specimens before and after drying were analyzed separately using X-ray computed tomography(CT),and flexural and compressive strengths for all specimens before and after drying were tested respectively.The experimental results show that the interface between AAS and PC is inclined to crack during humidity reduction,as the shrinkage resistance for both materials varied,and that leads to deterioration of microstructure and decrease of mechanical properties for the printout.Despite that,PC effectively remedies the strength insufficiency of AAS,and the flexural and compressive strengths for AAS-PC composite specimens are thus better as compared to printed specimens using AAS.Comparing between layer-by-layer and line-by-line printing method,the former one produces specimens with better flexural strength,while the latter one produces specimens with better compressive strength.The above results offer guidances for promotion and application of 3D printing technique.

关 键 词：3D打印 交替打印 微结构 碱激发矿渣 硅酸盐水泥 增材制造 

分 类 号：TU528[建筑科学—建筑技术科学]