摘要
为研究碱-盐复合激发大掺量矿渣充填胶凝材料的力学特性,设计不同石膏与熟料质量比的充填胶结体强度实验。利用XRD,SEM和TG-DSC等手段,研究净浆试样水化产物种类、微观形貌及质量损失率;基于室内实验研究成果,开展新型充填胶凝材料工业化应用研究。研究结果表明:当复合激发剂掺量为15%、石膏和熟料质量比为1:4,充填体3 d抗压强度最大为1.05 MPa;当复合激发剂掺量为20%、石膏和熟料质量比为3:2,充填体28 d抗压强度最大为8.61 MPa。石膏促使浆体中钙矾石(缩写为AFt)的生成,但掺量过大则影响早期胶凝物质的生成量,后期浆体中水化硅酸钙凝胶(缩写为C-S-H)的钙硅比由1.804降低到1.559,可保证结石体后期钙矾石的持续生成;3 d龄期净浆试样质量损失率从大到小依次为T7,T9和T6,28 d龄期净浆试样质量损失率依次为T9,T7和T6;综合可见,针对大掺量矿渣充填胶凝材料,合理的石膏掺量有助于提高充填体早期强度;但当石膏掺量较大或熟料掺量少时,胶结体早期强度低但有利于后期强度的提高。当熟料质量分数为12%,石膏为3%,矿渣为85%时,充填体3 d抗压强度为2.7 MPa,7 d抗压强度为5.1 MPa,28 d抗压强度达到10.6 MPa,满足金川矿山对充填体强度的要求。
In order to study the mechanical properties of slag cementitious materials excited by alkali-salt complex,the strength tests of cementitious materials with different gypsum-clinker mass ratios were carried out.XRD,SEM and TG-DSC were used to study the types,micro-morphology and mass loss rate of hydration products.Based on the results of laboratory test,the industrial filling test of new filling cementitious material was carried out.The results show that when the dosage of composite activator is 15%,m(gypsum):m(clinker)is 1:4,3 d compressive strength of backfill reaches the maximum 1.05 MPa.When the dosage is 20%and m(gypsum):m(clinker)is 3:2,28 d compressive strength of backfill reaches 8.61 MPa.Gypsum promotes AFt formation in paste,but excessive addition affects the formation of early cementitious materials.The Ca/Si of C-S-H gel in paste decreases from 1.804 to 1.559 in late paste,which can ensure the continuous formation of ettringite in later stage of calculus.The mass loss rates of the cementitious materials at 3 d age is T7,T9 and T6,in descending order,and the mass loss rate of the cementitious materials at 28 d age is T9,T7 and T6.Comprehensive analysis shows that the reasonable amount of gypsum can help to improve the early strength of the backfill,but when the amount of gypsum is large and the amount of clinker is small,the early strength of the cement is low,but it is conducive to the improvement of the late strength.When the mass fractions of clinker,gypsum and slag is 12%,3%and 85%,the 3 d compressive strength is 2.7 MPa,the 7 d compressive strength is 5.1 MPa,and the 28 d compressive strength is 10.6 MPa,which meets the requirement of filling strength in Jinchuan Mine.
作者
李立涛
高谦
陈得信
吴凡
LI Litao;GAO Qian;CHEN Dexin;WU Fan(School of Civil and Resource Engineering,University of Science and Technology Beijing,Beijing 100083,China;Jinchuan Group Co.Ltd.,Jinchang 737100,China)
出处
《中南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2020年第2期489-498,共10页
Journal of Central South University:Science and Technology
基金
国家重点研发计划项目(2017YFC0602903)~~
关键词
复合激发
石膏与熟料质量比
充填体抗压强度
水化产物
质量损失率
工业化应用
compound excitation
mass ratio of gypsum to clinker
compressive strength of backfill
hydration products
mass loss rate
industrial application
