聚羧酸减水剂对磷酸镁水泥性能的影响  

Effects of polycarboxylate superplasticizer on properties of magnesium phosphate cement

作　　者：孙赫男 关岩 孙美硕[1,2] 卢俊伯 毕万利 罗旭东 SUN Henan;GUAN Yan;SUN Meishuo;LU Junbo;BI Wanli;LUO Xudong(School of Material and Metallurgy,University of Science and Technology Liaoning,Anshan 114051,China;Research Institute of Keda Fengchi Magnesium Building Materials,University of Science and Technology Liaoning,Anshan 114051,China)

机构地区：[1]辽宁科技大学材料与冶金学院,辽宁鞍山114051 [2]辽宁科技大学科大峰驰镁建材研究院,辽宁鞍山114051

出　　处：《辽宁科技大学学报》2021年第4期285-293,共9页Journal of University of Science and Technology Liaoning

基　　金：国家自然科学基金(51778101);国家重点研发计划(2020YFC1909304);国家自然基金联合基金(U1908227)。

摘　　要：以重烧氧化镁和磷酸二氢铵为主要原料,以硼砂为缓凝剂,加入聚羧酸减水剂(PCE)制备磷酸镁水泥(MPC),研究PCE的加入量对MPC的凝结时间、流动度、强度及软化系数的影响。并采用X射线衍射(XRD)分析MPC体系中的物相组成,利用Topas 6.0软件中的Rietveld方法定量分析MPC物相含量,用场发射扫描电镜(SEM)分析其微观形貌。实验表明,随着PCE加入量的增加,MPC流动度、凝结时间以及早期强度都呈现先上升后下降的趋势。当PCE加入量为4%时,MPC流动度达到248 mm,终凝时间为15 min,1.5 h强度达到36.4 MPa,28 d强度达到108.5 MPa,浸水28d后软化系数为0.91。浸水超过94 d后,MPC强度均明显下降,试样表面析出白色晶体,造成表面层结构疏松,但加入4%PCE的试样内部结构较致密,因此强度损失率较低。A magnesium phosphate cement(MPC)was prepared by adding polycarboxylate superplasticizer(PCE)into main raw materials of dead burned magnesia and ammonium dihydrogen phosphate with borax as the retarder.The effects of the PCE amount on the setting time,fluidity,mechanical strength,and softening coefficient of the MPC were studied.X-ray diffraction(XRD)was used to analyze the phase compositions of the MPC system.The Rietveld method,as implemented in Topas 6.0 software,was used to quantitatively ana-lyze the mineral phases in the MPC.A scanning electronic microscope(SEM)was used to analyze the micro-structure of the MPC.The results show that with the increase of the PCE amount,the fluidity,setting time,and early mechanical strength of the MPC rise first and then decline.When the PCE amount was 4%,the fluid-ity of the MPC reached 248 mm,the final setting time was 15 min,the compressive strength reached 36.4 MPa after 1.5 h and 108.5 MPa after 28 d,and the softening coefficient was 0.91 after immersion in water for 28 d.The compressive strength of the MPC decreased significantly after immersion in water for 94 d,and white crystals precipitated on the surface of the samples and resulted in a loose surface layer structure.Howev-er,the sample with 4%PCE addition exhibited a low strength loss rate due to its dense internal structure.

关 键 词：磷酸镁水泥 聚羧酸减水剂 耐水性 软化系数 凝结时间 

分 类 号：TU528.042[建筑科学—建筑技术科学]