HB-CSA与膨胀剂对3D打印混凝土收缩开裂性能的影响  

Effect of HB-CSA and Expansion Agent on Shrinkage and Cracking Performance of 3D Printing Concrete

作　　者：崔天龙 王里 马国伟 李之建 白明科 CUI Tianlong;WANG Li;MA Guowei;LI Zhijian;BAI Mingke(School of Civil and Transportation Engineering,Hebei University of Technology,Tianjin 300401,China;Tianjin Key Laboratory of Prefabricated Building and Intelligent Construction,Tianjin 300401,China;Yaobai Special Cement Technology R&D Co.,Ltd.,Xi'an 710100,China)

机构地区：[1]河北工业大学土木与交通学院,天津300401 [2]天津市装配式建筑与智能建造重点实验室,天津300401 [3]尧柏特种水泥技术研发有限公司,西安710100

出　　处：《材料导报》2022年第2期76-82,共7页Materials Reports

基　　金：国家自然科学基金项目(51808183,51878241);天津市自然科学基金项目(20JCYBJC00710);河北省自然科学基金优秀青年基金项目(E2021202039)。

摘　　要：3D打印材料因连续挤出的工艺要求,受限于喷嘴的尺寸,制备时一般使用细骨料。细骨料比表面积大,包裹骨料所需浆体多,造成胶凝材料占比高;无模逐层堆积建造的固有流程,提高了打印材料的水分蒸发速率,导致3D打印水泥基复合材料具有较高的收缩和开裂风险。为此,通过复掺高贝利特硫铝酸盐水泥(HB-CSA)和UEA膨胀剂制备低收缩3D打印水泥基复合材料,测试评估其可打印性、力学性能和收缩开裂性能。结果表明,单掺5%(质量分数,下同)的HB-CSA时,3D打印水泥基复合材料90 d的收缩率可降低约8%,早期开裂面积下降约35%,且流动度为190 mm,初凝时间为45 min,满足3D打印挤出工艺要求;5%的HB-CSA和10%的UEA膨胀剂复掺时,所制备材料90 d的收缩率可降低约30%,早期开裂面积下降约33%。Limited by the requirements of continuous extrusion process and the size of nozzle,3 D printing materials are usually fine aggregate compo-sites.Due to the large specific surface area of fine aggregate,printing composites need more slurry to wrap the aggregate,resulting in a high proportion of cementitious materials.The inherent layer-upon-layer stacking process improve the water evaporation rate of printing materials,leading to high shrinkage and cracking risks.3 D printing cement-based composites were prepared by mixing high Belite sulphoaluminate cement(HB-CSA)and UEA expansive agent,and the printability,mechanical properties and shrinkage cracking properties were experimentally tested and evaluated.The results show that the 90 d shrinkage rate and early cracking area of the prepared material can be reduced by 8% and 35% respectively when 5% HB-CSA is adopted.The flowability of the prepared material is 190 mm,and the initial setting time is 45 min,which can meets the requirements of 3 D printing extrusion process;when 5% HB-CSA and 10% UEA expansion agent are mixed,the 90 d shrinkage rate and early cracking area of the prepared material can be reduced by 30% and 33% respectively.

关 键 词：3D打印混凝土 可打印性 收缩开裂 高贝利特硫铝酸盐水泥 UEA膨胀剂 

分 类 号：TU502[建筑科学—建筑技术科学]