摘要
为定量研究玻化微珠砂浆在搅拌过程中骨料分布均匀性受搅拌条件的影响,对新拌玻化微珠砂浆中的骨料进行分离,并根据分离得到的骨料与砂浆质量占比,定义了评价新拌砂浆中骨料分布均匀性的均匀度指数。试验结果表明:新拌砂浆中骨料分布均匀性随搅拌时间的延长呈先优化后劣化的变化趋势,搅拌过程中存在最优均匀度;卧式与立式搅拌机均在搅拌至4 min时达到最佳均匀度,卧式搅拌机的新拌砂浆中骨料分布均匀度优于立式搅拌机;玻化微珠骨料参与搅拌的时间相同时,采用先搅拌后投入玻化微珠骨料的方式能够优化骨料分布的均匀性。更高的搅拌机转速能更快提升新拌玻化微珠砂浆均匀度,但是较低的搅拌机转速下拌和的新拌玻化微珠砂浆极限均匀度更优,达到极限的耗时更长。
In order to quantitatively study the uniformity of aggregate distribution during the stirring process of glazed hollow bead mortar, the aggregate of the fresh glazed hollow bead mortar was separated. According to the mass ratio of aggregate and mortar obtained by separation, the uniformity index for evaluating the uniformity of aggregate distribution in fresh mortar is defined. The test results show that the uniformity of aggregate distribution in fresh mortar is firstly optimized and then deteriorated with the extension of stirring time, and the optimum uniformity exists during the mixing process. Both horizontal and vertical mixers achieve optimum uniformity when stirred for 4 minutes. The uniformity of aggregate distribution in the new mortar of the horizontal mixer is better than that of the vertical mixer; when the glazed hollow bead aggregates participate in the same stirring time, the uniformity of aggregate distribution can be optimized by first mixing and then feeding into vitrified microbead aggregates. Higher mixer speeds can increase the uniformity of fresh glazed hollow bead mortar faster, but the fresh glazed hollow bead mortar blended at lower mixer speeds has better uniformity and longer time to limit.
引文
[1]周静海,郭易奇,王晓天,等.骨料分布对再生混凝土抗压强度的影响[J].混凝土,2017(4):25-28.
[2]杜敏,金浏,李冬,等.模型尺寸和骨料级配对混凝土细观非均质影响[J].应用基础与工程科学学报,2017,25(2):382-394.
[3]周立民.玻化微珠保温砂浆性能优化研究[D].重庆:重庆大学,2015.
[4]戴海霞.搅拌时间对无机保温砂浆性能影响的研究[J].工程质量,2014,32(7):59-61.
[5]小原孝之.材料拌和离散元模拟系统的开发与应用[D].北京:清华大学,2007.
[6] SHASTRI, Dipendra; KIM, Ho Sung. A new consolidation process for expanded perlite particles[D]. Construction and Building Materials,2014,60:1-7.
[7]邓熔.搅拌车中混凝土流变性研究及应用[D].湘潭:湘潭大学,2016.
[8]刘扬,韩燕龙,贾富国,等.椭球颗粒搅拌运动及混合特性的数值模拟研究[J].物理学报,2015,64(11):258-265.