脱硫石膏基自流平砂浆的制备与性能研究

Preparation and Performance Study of Self-leveling Mortar for Desulfurization Gypsum

目的以脱硫石膏为主要胶凝材料,通过优化材料组成制备出主要性能满足相关标准要求的石膏基自流平砂浆。方法将脱硫石膏、水泥、细砂、减水剂和缓凝剂等组分按不同比例混合,以力学性能、30 min流动度为考查指标,设计单因素试验,探讨各组分用量对自流平砂浆性能的影响。结果随水灰比的增加,脱硫石膏净浆流动度增加,力学性能降低;减水剂掺量增加会使脱硫石膏净浆的30 min流动度提高,力学性能降低;掺入普通硅酸盐水泥能明显提高净浆30 min流动度以及抗折、抗压强度;随细砂掺量的增加,脱硫石膏基自流平砂浆的30 min流动度降低,抗折强度明显降低,抗压强度在细砂掺量为40%后明显降低。结论经优化后配制出的脱硫石膏基自流平砂浆的力学性能和30 min流动度满足《石膏基自流平砂浆》要求。

With desulfurized gypsum as the main cementing material,gypsum based self-leveling mortar whose main properties meet the requirements of relevant standards was prepared by optimizing the composition of the material.Desulphurized gypsum,cement,fine sand,water reducing agent and retarder were mixed in different proportions,and a single factor test was designed to investigate the influence of the amount of each component on the performance of self-leveling mortar with mechanical properties and 30 min fluidity as the test index.The experimental results show that with the increase of water-cement ratio,the fluidity of desulfurized gypsum slurry increases and the mechanical properties decrease.The 30 min fluidity of desulfurized gypsum slurry is increased and the mechanical properties are decreased with the increase of water reducing agent content.The addition of Portland cement can obviously improve the 30 min fluidity,flexural and compressive strength of the paste.With the increase of the content of fine sand,the 30 min fluidity of desulfurized gypsum self-leveling mortar decreases,the bending strength decreases obviously,and the compressive strength decreases obviously when the content of fine sand is 40%.The mechanical properties and 30min fluidity of the optimized desulfurized gypsum self-leveling mortar meet the G20 grade requirements of“Gypsum based self-leveling compound for floor”(JC/T1023-2021).