Drying shrinkage characteristics of low quality fly ash plastering mortar
CUI Zizhi
LIU Yan
NING Tao
HAN Dong
Abstract：The influence of water binder ratio,replacement rate and super adding rate of fly ash,and lignin fiber content on drying shrinkage property of plastering mortar was studied by orthogonal test,and multivariate nonlinear regression model of plastering mortar drying shrinkage were established using least square method.The optimal combination of M15 plastering mortar was put forward as follow:water/binder ratio as 0.60,replacement ratio of fly ash as 40％,excess ratio of fly ash as 15％,doping ratio of lignin fiber as 0.2％.The results show that equivalent replacement of cement with fly ash or addition of lignin has obvious inhibition effect on the drying shrinkage of mortar,super addition of low quality fly ash slightly enlarges the shrinkage of mortar,however,the influence is not significant;The drying shrinkage of mortar increases with the age,which increases rapidly in the early period and slowly in the later,more than 80％ of the total shrinkage of mortar has been completed within 28 d,so that the early period is the best stage for decreasing the drying shrinkage of mortar;The deviation of mortar shrinkage between the measured value and the predicted value is small,therefore the prediction results of the model are accurate and reliable.
Keywords：plastering mortarlow quality fly ashdrying shrinkageregression model
Publication Date：2017-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：4( 13-16 )