【作者】 马保国； 郅真真； 孙仲达； 苏英； 黄健； 郭炎飞；

【Author】 MA Baoguo;ZHI Zhenzhen;SUN Zhongda;SU Ying;HUANG Jian;GUO Yanfei;School of Materials Science and Engineering,Wuhan University of Technology;School of Civil Engineering,Architecture and Environment,Hubei University of Technology;School of Civil Engineering and Architecture,Wuhan University of Technology;

【机构】 武汉理工大学材料科学与工程学院； 湖北工业大学土木建筑与环境学院； 武汉理工大学土木工程与建筑学院；

【摘要】 基于建筑3D打印成型工艺,将石膏无机非金属胶凝材料应用于建筑3D打印,控制石膏胶凝材料高流态向固态的快速转变过程是关键因素。本文通过研究不同硫酸盐对石膏快速反应材料凝结时间、水化电导率、力学强度、膨胀率的变化,分析了硫酸盐对石膏水化过程的影响规律。结果表明:加入15%的硫酸盐（0.05mol）后,石膏浆体的初凝时间显著加快,由空白样的17min43s变为5min26s（Li⁺）,3min55s（Na⁺）和1min50s（K⁺）,为石膏快速反应材料在3D建筑打印上的应用提供了前提;石膏硬化体早期强度也显著提高,5min可达到4.5MPa左右,膨胀率降低,空白二水石膏膨胀率为0.17%,15%K₂SO₄加入后的膨胀率仅为0.06%,可以提高石膏打印的精度和稳定性。同时,通过对石膏晶体XRD的分析揭示硫酸盐对石膏水化影响的机理,阳离子进入硫酸钙晶体内部,形成具有一定强度的硫酸钙复盐,降低了晶体在（020）面上的成核位垒,促进二水硫酸钙晶核的形成,加快了石膏水化的时间。更多还原

【Abstract】 Based on the molding process of 3 D building printer,take gypsum inorganic nonmetallic material applied to the 3 D building printer,the key factor is controlling the rapid transformation process of self—leveling state to hardened state of gypsum cementitious materials.This paper study the effect of sulfate sate on the change of setting time,conductivity,mechanical strength and expansion rate of gypsum rapid reaction materials and analyses the influence rules of sulfate salt on gypsum hydration process.Results show that adding the 15%sulfate salt（0.05 mol）,the setting time of gypsum slurry increase obviously from 17 min43 s of control sample to 5 min26 s（Li⁺）,3 min55 s（Na⁺） 和 lmin50 s（K⁺）,which provided the premises for application of gypsum rapid reaction materials in 3 D building printer field.The early strength of gypsum hardened also improve significantly,the strength of which can reach4.5 MPa,and the expansion rate decrease.The expansion rate of control dihydrate gypsum is0.17%,which is only 0.06%of 15%K₂ SO₄,and could improve the accuracy and stabilization of gypsum printing.At the same time,the mechanism of sulfate salt on gypsum hydration through XRD analysis.The positive ions can into the inter of sulfate calcium crystal and form the complex salts with certain strength,which decrease the potential barrier of nucleation on the（020） surface of crystal and improve the formation of dihydrate gypsum crystal nucleus,so increase the hydration time.更多还原