基于孔结构缺陷的3D打印粗骨料混凝土力学性能试验研究  

Experimental study on mechanical properties of 3D printed coarse aggregate concrete based on the pore structure defects

作　　者：刘化威 刘超[1,2] 白国良 武怡文[1,2] Liu Huawei;Liu Chao;Bai Guoliang;Wu Yiwen(School of Civil Engineering,Xi'an University of Architecture and Technology,Xi'an 710055,China;Key Lab of Structure Engineering and Earthquake Resistance of the Ministry of Education,Xi'an University of Architecture and Technology,Xi'an 710055,China)

机构地区：[1]西安建筑科技大学土木工程学院,陕西西安710055 [2]西安建筑科技大学结构工程与抗震教育部重点实验室,陕西西安710055

出　　处：《土木工程学报》2022年第12期54-64,共11页China Civil Engineering Journal

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(2020JC-46);陕西省创新人才推进计划(2018KJXX-056);陕西省重点研发计划项目(2018ZDCXL-SF-03-03-02);陕西省科技创新基地(2017KTPT-19)。

摘　　要：文章基于目前3D打印混凝土结构缺少粗骨料的应用现状,针对高粗骨料掺量的3D打印混凝土开展破坏机理研究,重点围绕区别于以往浇筑建造模式下的3D打印粗骨料混凝土(3DPCAC)内部特有孔隙缺陷特征,对其力学性能的影响进行分析。研究结果表明:3DPCAC抗压和抗弯强度表现出显著的各向异性力学性能差异;粗骨料的掺入改变了以往3D打印混凝土层间黏结界面的开裂形式,黏结强度提高1.14倍;内部缺陷的几何形状特征与孔隙率分布发生显著的变化。基于孔隙结构缺陷及其分布特征,提出“多重分区-界面模型”,揭示孔隙缺陷对3DPCAC力学性能的影响机理。研究成果为3D打印混凝土结构设计与应用提供重要的理论支撑。In view of the current status of 3D printed concrete structures lacking coarse aggregate, the damage mechanism of 3D printed concrete with high-percentage coarse aggregate was investigated, and the influence of pore defect characteristics in 3D printed coarse aggregate concrete(3DPCAC) on its mechanical properties was analyzed.The results show that the compressive and flexural strengths of 3DPCAC exhibit significant differences in anisotropic mechanical property.The incorporation of coarse aggregates may change the cracking form of the bond interface between the layers of 3D printed concrete and increase the bond strength by 1.14 times.Geometric characteristics of internal defects and distribution of porosity change significantly.Based on the characteristics of pore structure defects and their distribution, a“multiple partition-interface model”was proposed to reveal the influence mechanism of the pore defects on the mechanical properties of 3DPCAC.The research results can provide important theoretical support for the design and application of 3D printed concrete structures.

关 键 词：3D打印混凝土 粗骨料 孔隙缺陷 

分 类 号：TU528[建筑科学—建筑技术科学]