返回叶片数量及排布方式对混凝土搅拌均匀性的影响  

Influence of number and arrangement pattern of reversing blade on mixing uniformity of concrete

作　　者：赵利军[1] 余志龙[1] 徐鹏杰[1] 丁渭渭 

机构地区：[1]长安大学道路施工技术与装备教育部重点实验室,陕西西安710064

出　　处：《长安大学学报（自然科学版）》2016年第4期103-110,共8页Journal of Chang’an University(Natural Science Edition)

基　　金：陕西省重大科技创新项目(2008ZKC 01-16);中央高校基本科研业务费专项资金项目(CHD2011JC093)

摘　　要：为了提高混凝土的搅拌均匀性,在普遍使用的双卧轴搅拌机上,通过改变搅拌叶片总数量不变条件下的返回叶片数量以及连续和非连续的排布方式,分析了对搅拌过程中混凝土混合料围流运动的影响,并在相同混凝土配合比和投料顺序、搅拌时间下,通过4种拌缸长宽比(长宽比为0.8和0.9的宽短形,1.1和1.2的窄长形)的搅拌性能试验,采用新拌混凝土拌合物中砂浆密度和单位体积粗骨料质量变异系数的均匀性分析方法,确定了双卧轴搅拌机返回叶片的合理数量与排布方式。研究结果表明:对于不同的返回叶片数量与排布方式,搅拌机内的轴向和轴间循环运动随之改变,因而给定搅拌时间内的搅拌均匀性发生变化;与排布方式相比,返回叶片数量对搅拌均匀性的影响程度更为显著;合理的单轴返回叶片数量与单轴搅拌叶片总数量和拌缸长宽比形式密切相关,建议宽短形拌缸的单轴返回叶片数量与单轴叶片总数量的比值控制在0.2以内,窄长形拌缸的控制在0.3以内;单轴返回叶片数量在1个以上时,建议返回叶片采用非连续正排列方式,以促使返回料流快速形成。In order to improve the mixing uniformity of concrete mixture for twin-shaft mixer, influence of the number of reversing blade, continuous and discontinuous arrangement of multi reversing blade under the constant number of mixing blades on circulation of the mixture movement in mixer were analyzed. Through mixing performance experiments of four different length-width ratio of mixer trough （0.8 and 0.9 for short-wide mixer trough, 1. 1 and 1.2 for long-narrow mixer trough） under the same conditions of concrete composition, mixing procedure and mixing time, reasonable number and arrangement pattern of the reversing blade were determined by analyzing the variation coefficients of mortar density and coarse aggregate mass per unit volume in freshly mixed concrete. The results show that mixing uniformity within a given time varies with the different number and arrangement pattern of reversing blade since axial movement and inter-axis movement of mixture in the mixer trough change. Compared with the arrangement pattern,the number of reversing blade has greater effect on mixing uniformity. The reasonable number of reversing blade on single shaft is closely related to the total number of mixing blade on single shaft and length-width ratio of mixer trough. It＇s suggested that the ratio of number of reversing blade on single shaft to the total number of mixing blade on single shaft should be controlled within 0. 2 for short-wide mixer trough, and 0. 3 for long narrow mixer trough. When the number of reversing blade on single shaft is 2 and above, discontinuous- positive arrangement of the reversing blade is recommended to develop reversing flow of the mixture movement rapidly. 6 tabs, 6 figs, 20 refs.

关 键 词：机械工程 双卧轴搅拌机 返回叶片 叶片数量 排布方式 搅拌均匀性 

分 类 号：U415.522[交通运输工程—道路与铁道工程]