Influence of Admixtures on Properties of Traditional Sticky Rice-lime Mortar and Their Mechanisms

On the basis of characterization of property of traditional sticky rice-lime mortar,influence of admixtures(aluminum sulfate,gypsum,paper fiber) on properties of traditional sticky rice-lime mortar and their scientific mechanisms are discussed by means of SEM and XRD.It is indicated that paper fiber is the most effective admixture to endure freezing-thawing cycles and increase compressive strength of sticky rice-lime mortar due to disorderly distribution and water-retaining of paper fiber,and the use of aluminum sulfate reduces dry shrinkage values and improves compressive strength because of formation of ettringite in sticky rice-lime mortar.Gypsum is proved to be ineffective to modify freezing-thawing cycles of sticky rice-lime mortar.Meanwhile,compressive strength and surface hardness of sticky rice-lime mortar with gypsum decline as gypsum amounts.It is suggested that 6% aluminum sulfate or 3% paper fiber can be used as admixtures of sticky rice-lime mortar in conservation of cultural relics.