资源描述：
《粉煤灰砂浆自生收缩和干燥收缩关系的研究.pdf》由会员上传分享，免费在线阅读，更多相关内容在行业资料-天天文库。
1、第31卷第5期硅酸盐学报Vol131,No152003年5月JOURNALOFTHECHINESECERAMICSOCIETYMay,2003粉煤灰砂浆自生收缩和干燥收缩关系的研究1,21严捍东,孙 伟(11东南大学材料科学与工程系,南京 210096;21华侨大学土木工程系,福建 泉州 362011)摘 要:为了揭示粉煤灰对水泥基材料自生收缩和干燥收缩间的定性和定量关系,分别测定了质量分数为0130,0145和0160的超细低钙粉煤灰或I级低钙粉煤灰砂浆从加水养护1d至120d的自生收缩(ε1)和干燥收缩应变值(ε2)。试验结果表
2、明,早期(7d内)粉煤灰砂浆的自生收缩会比基准砂浆低,粉煤灰对砂浆自生收缩的作用受到粉煤灰自身活性和粉煤灰取代水泥质量分数的影响,粉煤灰活性高,其砂浆早期自身a-b收缩大,后期自身收缩随粉煤灰取代水泥质量分数的增加而减小。提出的回归模型ε1/ε2=et能够很好地反映随时间延长,水泥基材料自生收缩在总干燥收缩中所占的比率。关键词:超细低钙粉煤灰;I级低钙粉煤灰;砂浆;自生收缩;干燥收缩中图分类号:TQ172文献标识码:A文章编号:0454-5648(2003)05-0428-06STUDYONTHERELATIONSHIPBETWEE
3、NAUTOGENOUSSHRINKAGEANDDRYINGSHRINKAGEOFFLYASHMORTAR1,21YANHandong,SUNWei(11DepartmentofMaterialsScienceandTechnology,SoutheastUniversity,Nanjing210096;21DepartmentofCivilEngineering,HuaqiaoUniversity,Quanzhou,Fujian362011,China)Abstract:Inordertorevealthequalitativean
4、dquantitativerelationshipbetweenautogenousshrinkageanddryingshrinkageofthece2ment2basedmaterials,theautogenousshrinkage(ε1)anddryingshrinkagestrainvalue(ε2)ofthemortarscontaining0130,0145and0160ofmassfractionofsuperfineorGradeIclassFflyash,curedfrom1dayto120daysafterad
5、dingwater,weremeasuredre2spectively1Experimentalresultsdemonstratethattheautogenousshrinkagestrainvalueofflyashmortarislowerthanthatofrefer2encemortarwithinthefirstsevendays1Theinfluenceofflyashontheautogenousshrinkageofthemortarisdependedontheactivityoftheflyashandthe
6、massfractionoftheflyashforreplacingthecement1Thehighertheactivityofflyashis,thelargertheautoge2nousshrinkageofthemortarwillbeattheearlystage1Theautogenousshrinkageofthemortaratthelaterstageisreducedwiththeincreaseofthemassfractionoftheflyashduetothereplacementoftheceme
7、nt1Thechangefortherateofautogenousshrinkagetodryingshrinkageofcement2basedmaterialswiththetimeextensionofthecurediswellillustratedbytheregressionmodelobtained1Keywords:superfineclassFflyash;GradeIclassFflyash;mortar;autogenousshrinkage;dryingshrinkage 干燥收缩和自生收缩都是由于硬化水
8、泥浆体毛缩是因水泥基材料周围环境中的相对湿度较低,孔细孔中的水分减少,使得部分毛细孔不能被水饱和,隙中的水分被蒸发到空气中而丧失。自生收缩是当亲水性的毛细孔壁使得毛细孔内水面呈弯月面,使水泥浆体处于一个与外界没有水分交换的情况下,毛细
