引气剂对轻质抹灰石膏性能的影响研究

The research on the effect of air entraining agent on properties of lightweight gypsum plaster

研究了3种不同种类的引气剂对轻质抹灰石膏砂浆含气量、湿密度、施工性的影响规律;研究了含气量与砂浆塑性抗裂性的关系以及纤维素醚和引气剂的协同作用。结果表明:相同掺量时,不同种类的引气剂对轻质抹灰石膏含气量影响差异较大。选用引气剂时,应综合考虑生产线计量设备精度、混合主机混合效率等因素。可采用生产前试配的方式确定引气剂的掺量。对于同种引气剂,随着引气剂掺量的增加,砂浆的含气量逐渐增大、湿密度逐渐减小。在一定范围内,引气剂掺量的增加有助于改善轻质抹灰石膏砂浆的施工性和抗裂性。纤维素醚掺量的增加能够提高轻质抹灰石膏含气量;增加纤维素醚掺量时,应适当降低引气剂掺加量。综合考虑轻质抹灰石膏砂浆的性能,建议湿砂浆的含气量控制在28%~35%为宜。

Three different kinds of air entraining agents were researched on the properties of lightweight gypsum plaster,such as air content,wet bulk density,workability.The relationship between air content and crack resistance and the synergistic effect of cellulose ether and air entraining agent were studied.The results show that different kinds of air entraining agents have different effects on the air content of lightweight gypsum plaster at the same dosage.When selecting the type of air entraining agent,factors such as the accuracy of metering equipment of production line and the mixing efficiency of mixing machine shall be comprehensively considered.The mixing amount of air entraining agent can be determined by trial preparation before production.For the same kind of air entraining agent,with the increase of air entraining agent content,the air content of mortar gradually increases and the wet bulk density gradually decreases.In a certain range,the increase of air entraining agent is helpful to improve the workability and crack resistance of lightweight gypsum plaster.The increase of cellulose ether content can improve the air content.When increasing the cellulose ether content,the air entraining agent content should be appropriately reduced.Considering the performance of lightweight gypsum plaster,it is suggested that the air content of wet mortar should be controlled at 28%~35%.