摘要
研究了陈化方式和陈化时间对建筑石膏物相组成及物理性能影响,重点研究了陈化时间对底层抹灰石膏砂浆、轻质抹灰石膏砂浆、石膏基自流平砂浆凝结时间、施工性影响规律。研究表明:陈化方式对建筑石膏陈化速率影响显著,透气性良好的编织袋陈化效果明显好于木桶陈化效果;随着陈化时间的延长,建筑石膏中Ⅲ型无水石膏含量逐渐减少,最终消失,附着水含量逐渐增加,标准稠度用水量显著降低,凝结时间略有增加,陈化时间过长时,建筑石膏2h强度出现明显降低。随着建筑石膏陈化时间的延长,配制的底层抹灰石膏砂浆、轻质抹灰石膏砂浆、石膏基自流平砂浆凝结时间均出现大幅延长。轻质抹灰石膏砂浆过度陈化时,会导致砂浆粘聚性减低,出现“发糟”等现象,严重影响其施工性能。石膏基自流平砂浆过度陈化时,容易出现泌水等情形,严重影响其硬化后表面平整度。因此,实际生产时,应严格控制建筑石膏陈化时间,避免出现过度陈化,导致石膏砂浆出现质量问题。
The effects of aging method and aging time on the phase composition and physical properties of calcined gypsum are studied.The effects of aging time on the setting time and constructability of ordinary gypsum plaster mortar,light gypsum plaster mortar and gypsum based self-leveling compound for floor are studied.The results show that the aging method has a significant effect on the aging rate of building gypsum,and the aging effect of woven bag with good air permeability is significantly better than that of wooden barrel;With the extension of aging time,the content oftype Ⅲ anhydrous gypsum in calcined gypsum gradually decreases and finally disappears,the content of attached water gradually increases,the water consumption of standard consistency decreases significantly,and the setting time increases slightly.When the aging time is too long,the 2h strength of calcined gypsum decreases significantly.With the extension of the aging time of calcined gypsum,the setting time of the prepared ordinary gypsum plaster mortar,light gypsum plaster mortar and gypsum based self-leveling compound for floor has been greatly prolonged.When the light gypsum plaster mortar is over aged,it will lead to the reduction of mortar cohesion and"deterioration",which will seriously affect its constructability.When gypsum based self-leveling compound for floor is over aged,it is prone to bleeding,which seriously affects the surface flatness after hardening.Therefore,in actual production,the aging time of calcined gypsum should be strictly controlled to avoid excessive aging,resulting in quality problems of gypsum mortar.
出处
《混凝土世界》
2023年第2期60-63,共4页
China Concrete
关键词
陈化时间
物相组成
石膏砂浆
凝结时间
施工性
Aging time
phase composition
gypsum mortar
setting time
constructability