古建筑琉璃瓦抗冻融性影响因素探究

Study on the factors influencing the freeze-thaw resistance of ancient architectural glazed tiles

自然环境中的冻融作用不仅会造成琉璃样品表面釉层脱落,还会导致胎体断裂等严重破坏.以清代琉璃瓦及现代烧制琉璃瓦为研究对象,分析胎体和釉层的化学组成、形貌、致密度、显气孔率、吸水率、抗冻融性等.结果发现,冻融产生的破坏主要为胎体开裂和釉层脱落两种类型,部分样品在釉面脱落的同时带下了相邻的胎体.现代烧制琉璃瓦整体上呈现较好的抗冻融性能,较低的胎体吸水率可提高琉璃瓦的抗冻融性能,胎釉中间层尤其是化妆土层可缓解冻融过程中胎体体积的变化对釉层的破坏;在烧制条件相同时,Al 2O 3含量的降低与K 2O含量的升高有利于提高胎体的烧结程度,进而提高琉璃瓦的抗冻融性能,研究成果可为古建筑修缮提供一定的科学依据.

The freeze-thaw effect in the natural environment will not only cause the glaze layer on the surface of the glazed sample to fall off,but also lead to serious damage such as fracture of body.Taking glazed tile of Qing Dynasty and modern fired glazed tile as research object,the chemical composition,morphology,density,apparent porosity,water absorption and freeze-thaw resistance of glazed tile were analyzed.The results show that the damage caused by freeze-thaw mainly falls into two types:body cracking and glaze shedding,and some samples take down the adjacent body while the glaze falls off.Modern fired glazed tiles generally exhibit good freeze-thaw resistance,and lower body water absorption can improve the freeze-thaw resistance of glazed tiles.The intermediate layer of the body glaze,especially the makeup layer,can alleviate the damage of the glaze layer caused by the volume change of the body during the freeze-thaw process.Under the same firing conditions,the decrease of Al 2O 3 content and the increase of K 2O content are beneficial to improve the sintering degree of the body.The research results can provide a scientific basis for the repair of ancient buildings.