粉煤灰改性磷酸镁水泥性能及机理分析  

Performance and Mechanism Analysis of Magnesium Phosphate Cement Modified by Fly Ash

作　　者：朱金才 李超众 闫长旺 孟晓凯[4] ZHU Jincai;LI Chaozhong;YAN Changwang;MENG Xiaokai(School of Civil Engineering,Inner Mongolia University of Technology,Hohhot 010051,China;Key Laboratory of Civil Engineering Structure and Mechanics,Inner Mongolia Autonomous Region,Hohhot 010051,China;School of Mining and Technology,Inner Mongolia University of Technology,Hohhot 010051,China;College of Science,Inner Mongolia University of Technology,Hohhot 010051,China)

机构地区：[1]内蒙古工业大学土木工程学院,内蒙古呼和浩特010051 [2]内蒙古自治区土木工程结构与力学重点实验室,内蒙古呼和浩特010051 [3]内蒙古工业大学矿业学院,内蒙古呼和浩特010051 [4]内蒙古工业大学理学院,内蒙古呼和浩特010051

出　　处：《材料科学与工程学报》2024年第2期262-268,共7页Journal of Materials Science and Engineering

基　　金：国家自然科学基金资助项目(52168031);内蒙古自然科学基金资助项目(2020BS05012);内蒙古自治区高等学校科学研究资助项目(NJZY19087,NJZY21331);内蒙古工业大学重点资助项目(ZZ201912)。

摘　　要：以粉煤灰、MgO和KH_(2)PO_(4)为原料制备磷酸镁水泥(MPC)。测定MPC在不同粉煤灰掺量下的抗压强度、抗折强度、凝结时间、孔隙率,并分析其微观结构。研究结果表明:MPC抗压强度随粉煤灰掺量的增加先升高后降低,掺量为20%时强度最大为34 MPa,抗折强度随粉煤灰掺量的增加而降低,韧性随粉煤灰掺量的增加而降低;粉煤灰改善了MPC孔结构,粉煤灰掺量为40%时MPC孔隙率降低了67.2%;粉煤灰延长了MPC凝结时间,粉煤灰掺量为40%时MPC凝结时间延长至13.7 min;随着粉煤灰掺量的增加水化产物MgKPO_(4)·6H_(2)O(MKP)生成量先增多后减少,粉煤灰掺量20%时MKP生成量最大。粉煤灰对MPC强度的影响主要取决于MKP生成量。Magnesium phosphate cement(MPC)was prepared with fly ash,MgO and KH_(2)PO_(4) as raw materials.The compressive strength,flexural strength,setting time and porosity of MPC under different fly ash contents were measured,and the microstructure was analyzed.The test results show that the compressive strength of MPC increases first and then decreases with the increase of fly ash content.When the fly ash content is 20%,the maximum compressive strength is 34 MPa.The flexural strength decreases with the increase of fly ash content,and the toughness also decreases with the increase of fly ash content.The addition of fly ash improves the pore structure of MPC,and when the fly ash content is 40%,the porosity of MPC decreases by 67.2%.Fly ash prolongates MPC setting time,and the setting time extends to 13.7 min when the fly ash content is 40%.With the increase of fly ash content,the production of hydration product MgKPO_(4)·6H_(2)O(MKP)increases first and then decreases,and the MKP production is the largest when the content is 20%.The effect of fly ash on the MPC strength mainly depends on the MKP production.

关 键 词：磷酸镁水泥 粉煤灰 抗压强度 微观结构 MKP生成量 

分 类 号：TU525.9[建筑科学—建筑技术科学]