材料组成对3D打印水泥基材料早龄期收缩的影响  

Effect of Material Composition on Early Age Shrinkage of 3D Printed Cement-Based Materials

作　　者：郝鹏宇 王振地 王玲 HAO Pengyu;WANG Zhendi;WANG Ling(State Key Laboratory of Green Building Materials,China Building Materials Academy,Beijing 100024,China)

机构地区：[1]中国建筑材料科学研究总院有限公司,绿色建筑材料国家重点实验室,北京100024

出　　处：《硅酸盐学报》2025年第1期84-94,共11页Journal of The Chinese Ceramic Society

基　　金：中国建材集团原创技术策源地项目(2021YCJS01-2-1);吴中伟青年科技奖项目(ZA-100)。

摘　　要：由于胶凝材料用量大、通常不使用粗骨料、缺乏模板保护且打印后立即暴露等原因,3D打印水泥基材料(3DPC)的收缩问题值得系统研究。为掌握典型材料组成对3DPC收缩的影响规律,采用接触式收缩测试方法,研究了水胶比、砂胶比、粉煤灰及矿渣粉掺量对3DPC总收缩、自收缩及干燥收缩的影响,基于灰色关联分析计算了材料组成对3DPC收缩的影响程度,对比分析了现有砂浆体系的收缩特性。结果发现增大3DPC的水胶比降低自收缩的作用大于干燥收缩。在3d龄期后的干燥收缩随砂掺量的增加而减小。掺入粉煤灰可同比例地降低3DPC的14 d自收缩和干燥收缩,而掺入矿渣粉会增大2 d后的自收缩和5d前的干燥收缩。材料组成影响3DPC收缩的权重从大到小为:水胶比、砂胶比、矿渣粉掺量、粉煤灰掺量。通过综合对比给出了3DPC、超高性能混凝土和浇筑砂浆的收缩当量,建议对3DPC的收缩研究予以重视。Introduction The rapid adoption of 3D printed cement-based materials(3DPC)in construction industry,particularly in sustainable buildings,highlights a critical importance of understanding its shrinkage characteristics.Different from conventional concrete,3DPC is characterized due to the absence of coarse aggregates,the lack of templates support during printing,and immediately exposure to environmental conditions,which make it more susceptible to shrinkage-induced cracking.Shrinkage in cement-based materials leads to internal stresses and potential durability issues,affecting a long-term structural integrity.It is thus to investigate the shrinkage behavior of 3DPC.In particular,the effect of material compositions(i.e.,water-binder ratio(W/B),sand-binder ratio(S/B),and supplementary cementitious materials such as fly ash(FA)and ground granulated blast furnace slag(GGBS))on the shrinkage(total shrinkage,autogenous shrinkage,and drying shrinkage)is not fully clarified.This study was to investigate the shrinkage characteristics of 3DPC and compare it with other cement-based materials(i.e.,UHPC and cast mortar).Methods To investigate the impact of material composition on 3DPC shrinkage,a series of laboratory experiments were conducted by a standardized contact shrinkage testing method.Four key factors evaluated were W/B,S/B,FA replacement ratio,and GGBS replacement ratio.These material variables were selected based on their known influence on the microstructure and shrinkage behavior of traditional cement-based materials.Total shrinkage(TS),autogenous shrinkage(AS),and drying shrinkage(DS)were measured at specific intervals to capture early-age shrinkage behavior in 14 d.TS was calculated as a sum of AS and DS to represent the overall dimensional changes of the material for over time.The degree of influence of each material factor on the shrinkage was determined by grey relational analysis(GRA).GRA is a statistical method that enables the quantification of the relationship between multiple variables in complex systems,m

关 键 词：3D打印 水泥基材料 自收缩 干燥收缩 灰色关联分析 

分 类 号：TU528[建筑科学—建筑技术科学]