早强剂对粉煤灰-水泥砂浆力学性能的影响研究

Study of Early Strength Agent on the Performance of Fly Ash-cement Mortar

为解决装配式免拆模板的底板在生产过程中成型时间较长、使用模具数量较多的缺点,提高模具的周转率和水泥材料短期强度,以粉煤灰与水泥为原料,添加硫酸锂为激发剂,促进粉煤灰-水泥体系快速凝结。通过粉煤灰掺量和养护周期对水泥复合物影响的试验,得到粉煤灰掺量为30%时,粉煤灰-水泥体系的抗压性能和抗拉性能最优。通过不同掺量的硫酸锂对粉煤灰-水泥体系的抗压、抗折强度的试验研究,最终确定硫酸锂的掺量控制在0.6%时,粉煤灰-水泥体系的性能最优;采用粉煤灰∶水泥∶砂∶聚竣酸减水剂∶硫酸锂∶水=30∶100∶390∶2.3∶0.78∶125的质量比制成装配式建筑模板,并论述了装配式建筑免拆模板的生产工艺、制作流程、施工方法。

In order to solve the shortcomings of long molding time and large number of molds used in the production process of the bottom plate of assembled demolition-free formwork,and to improve the turnover rate of molds and short-term strength of cement materials,fly ash and cement were used as raw materials,and lithium sulfate was added as an excitation agent to promote the rapid setting of fly ash-cement system.Through the test of the effect of fly ash admixture and maintenance cycle on cement compound,the best compressive and tensile properties of fly ashcement system were obtained when the fly ash admixture was 30%.Through the test of the effect of mixing different amounts of lithium sulfate on the compressive and flexural strength of the fly ash-cement system,it was finally determined that the performance of the fly ash-cement system was optimal when the amount of lithium sulfate was controlled at 0.6%.The mass ratio of fly ash∶cement∶sand∶polyacid water reducing agent∶lithium sulfate∶water=30∶100∶390∶2.3∶0.78∶125 was used to make the assembled building formwork,and the production process,production procedure and construction method of assembled building free formwork were discussed.