石墨粉对磷石膏基自流平砂浆性能的影响  

Effects of graphite powder on properties of phosphogypsum based self-leveling mortar

作　　者：陈小江 刘川北[1] 高建明 刘来宝[1] 唐凯靖 张礼华[1] 辜涛 CHEN Xiaojiang;LIU Chuanbei;GAO Jianming;LIU Laibao;TANG Kaijing;ZHANG Lihua;GU Tao(School of Materials and Chemistry,Southwest University of Science and Technology,Mianyang 621000,China;Jiangsu Key Laboratory of Construction Materials,School of Materials Science and Engineering,Southeast University,Nanjing 211189,China;Department of Materials Engineering,Mianyang Vocational and Technical College,Mianyang 621000,China)

机构地区：[1]西南科技大学材料与化学学院,四川绵阳621000 [2]江苏省土木工程材料重点实验室,江苏南京211189 [3]绵阳职业技术学院材料工程系,四川绵阳621000

出　　处：《新型建筑材料》2023年第8期59-63,78,共6页New Building Materials

基　　金：东南大学江苏省土木工程材料重点实验室开放研究基金资助课题(202209);高性能土木工程材料国家重点实验室开放课题(2022CEM007)。

摘　　要：研究了2种不同粒径石墨粉及其掺量对磷石膏基自流平砂浆流动度、凝结时间、力学强度和导热系数的影响规律及作用机理。结果表明:随石墨粉替代胶凝材料质量的增加,砂浆流动度下降、凝结时间缩短、强度降低,导热系数线性上升。相同掺量下,掺入1200目石墨粉砂浆的流动度和力学强度损失更小,而掺入325目石墨粉砂浆的凝结时间缩短更慢、导热系数上升更快;石墨粉疏水团聚效应使砂浆流动度下降,而表面成核和微集料效应使砂浆凝结时间缩短,且可以弥补部分强度损失。高导热的石墨粉掺入会降低自流平砂浆内部热阻,形成导热通道,提高导热系数。当1200目石墨粉掺量为6%时,经优化的磷石膏基自流平砂浆性能满足JC/T 1023—2021《石膏基自流平砂浆》要求,且导热系数提高了37.1%。The effects of two kinds of graphite powders with different particle sizes and their contents on the fluidity,setting time,mechanical strength and thermal conductivity of phosphogypsum based self-leveling mortar were studied.The results show that the fluidity of mortar decreases,the setting time shortens,the strength decreases,and the thermal conductivity increases linearly with the increase of the mass fraction of cementitious material replaced by graphite powder.At the same dosage,the fluidity and mechanical strength loss of mortar mixed with 1200 mesh graphite powder are smaller,while the setting time of mortar with 325 mesh graphite powder is shortened more slowly and the thermal conductivity rises faster;The hydrophobic and agglomeration effects of graphite powder will reduce the fluidity of mortar,while its surface nucleation and micro aggregate effect will shorten the setting time of mortar and can make up part of the strength loss.Besides,the addition of graphite powder with high thermal conductivity will reduce the internal thermal resistance,form thermal conduction channels,and improve the thermal conductivity of self-leveling mortar.The optimized phosphogypsum based self-leveling mortar mixed with 6%1200 mesh graphite powder meets the requirements of the standard JC/T 1023—2021"Gypsum based self-leveling motor",and its thermal conductivity is increased by 37.1%.

关 键 词：自流平砂浆 磷石膏 石墨粉 流动度 导热系数 

分 类 号：TU526[建筑科学—建筑技术科学]