3D打印再生砂浆早期流变性能及结构经时演化研究  

Study on Early Rheological Properties and Structure Evolution of 3D Printed Recycled Mortar

作　　者：刘超[1,2] 蒙毅升 武怡文 刘化威 LIU Chao;MENG Yisheng;WU Yiwen;LIU Huawei(School of Science,Xi'an University of Architecture and Technology,Xi'an 710055,China;School of Civil Engineering,Xi'an University of Architecture and Technology,Xi'an 710055,China)

机构地区：[1]西安建筑科技大学理学院,西安710055 [2]西安建筑科技大学土木工程学院,西安710055

出　　处：《材料导报》2024年第9期118-125,共8页Materials Reports

基　　金：“十三五”国家重点研发计划(2019YFC1907105);国家自然科学基金(51878546,52178251);陕西省杰出青年科学基金项目(2020JC-46);陕西省重点研发计划项目(2020SF-392);榆林市产学科技计划项目(CXY-2020-062);陕西省创新人才推进计划(2018KJXX-056)。

摘　　要：为深入探究再生砂浆在3D打印技术中的适用性,对不同取代率的再生砂浆开展研究,分析了再生砂浆的流/触变性在早期阶段的发展过程,采用数字图像技术对静载作用下3D打印试件的变形进行收集分析。结果表明:随着水化反应的进行,再生砂浆呈现较快的静态屈服应力和触变环面积的增长趋势,其20 min静态屈服应力为天然砂浆的1.47倍,表现出更好的可建造性。在荷载作用下再生砂浆打印试件的竖向突变高度损失和徐变位移明显较小,约为天然砂浆打印试件的1/2。根据再生砂表观特点揭示了水化过程中再生砂浆流/触变性的演化机理,从材料性能和3D打印试件结构空隙方面对3D打印试件在静载作用下的变形进行分析,为再生砂浆在3D打印中的使用提供理论支撑。In order to further explore the applicability of recycled mortar in 3D printing technology,this work studies the mortar with different replacement rates of recycled sand.The development process of flow/thixotropy of recycled mortar in the early stage is analyzed,digital image technology is used to collect and analyze the deformation of 3D printed specimens under static load.The results show that with the progress of hydration reaction,the recycled mortar shows a rapid growth trend of static yield stress and thixotropic ring area.The static yield stress of 20 min is 1.47 times that of natural mortar,showing better constructability.Under static load,the loss of vertical mutation height and creep of recycled mortar printed specimens are significantly smaller.It is about 0.5 times that of natural mortar printed specimens,according to the apparent characteristics of recycled sand,the evolution mechanism of flow/thixotropy of recycled mortar during hydration is revealed.The deformation of 3D printed specimen under static load is analyzed from the aspects of material properties and 3D printing time structure gap,which provides theoretical support for the application of recycled mortar in 3D printing.

关 键 词：3D打印 再生砂浆 早期性能 流变性 强度演化 

分 类 号：TU528[建筑科学—建筑技术科学]