Performance Research On Thick Layer Gypsum Base Self-leveling Mortar And Application In Home Decoration Area

Thick-layer gypsum-based self-leveling mortar is a new type of ground leveling material used in the field of home furnishings.With the improvement of the performance of ground decorative materials and the improvement of people’s living standards,the traditional cement mortar flat ground that has problems such as long construction cycle,cracking,smoothness,etc.,can not meet the installation requirements of large-size wood floor.Thick-layer gypsum-based self-leveling mortar has the characteristics of fast condensation hardening,low shrinkage,high smoothness and good strength,and is an ideal material for ground leveling in the field of home furnishings.However,there is still a lack of research on the formulation composition,additive selection and material construction of thick-layer gypsum based self-leveling mortar.By testing the flow degree,24 h strength,dry strength,bonding strength and shrinkage of thick-layer gypsum based self-leveling mortar,the optimum dosage,re-dispersed latex powder,polycarboxylic acid water reducer,cement,bentonite,cellulose ether,stabilizer,aggregate particle size and construction technology were studied.Formulation and construction scheme of thick-layer gypsum based self-leveling mortar were obtained.Through the study,the optimum formulation and construction scheme of thick-layer gypsum based self-leveling mortar were obtained,and two cases of home furnishings were formed.The mechanism of the action of the re-dispersed latex powder and stabilizer in gypsum-based self-leveling mortar was analyzed by SEM,and the relationship between the physical properties of the water reducer functional groups and the gypsum based self-leveling mortar was applied by infrared spectroscopy.The results of physical and mechanical properties test show that the addition of re-dispersible latex powder reduces the 24 h strength of gypsum base self-leveling,improves the absolute dry strength and bonding strength,improves the maximum dry flexural strength by 63.5%,and increases the maximum dry strength by 63.8%.The flow degree and strength of cement mixed with gypsum based self-leveling mortar showed an increasing trend,but the shrinkage of gypsum based self-leveling mortar increased.The type of polycarboxylic acid water reducer has a great influence on the setting time,flow degree and strength of gypsum.The addition of bentonite,cellulose ether and stabilizer reduced the bleeding rate of gypsum based self-leveling mortar,and the stabilizer had little effect on the flow degree and strength of gypsum based self-leveling mortar.Aggregate grade pairing gypsum based self-leveling mortar has a certain influence on the flow degree,strength and shrinkage,and the optimum allocation ratio of gypsum based self-leveling mortar to ISO standard sand is 7:3.The stirring mode has a great influence on the expansion performance of gypsum-based self-leveling mortar slurry,and the optimum stirring speed is 800-1000 turn/min,and the stirring time is 1min.SEM test showed that the mechanical properties of gypsum based self-leveling mortar were improved by the organic bridge formed between gypsum crystals and aggregates in gypsum based self-leveling mortar.Stabilizing agent swells in water to form a viscous solution to improve the viscosity of the solution,thus improving the thick layer gypsum base self-leveling mortar drainage.The thick layer gypsum based self-leveling mortar was successfully applied to the field of home furnishings.The performance meets the technical requirements.The compressive strength of 24 h is greater than 7MPa.The absolute dry compressive strength is greater than 25 MPa.