Influence of Mineral Particle Size on Mixing Time and Phase Mixing Technology
LIU Hong-hai;LIU-NIE Yang-zi;HAO Yu-fei;ZHENG Kun-long;SHAO Xiao-feng;Key Laboratory of Road Construction Technology and Equipment of Ministry of Education,Chang'an University;School of Highway,Chang'an University;Inner Mongolia Highway Construction and Development Co.,Ltd;
In order to investigate the influence of the adding order of coarse aggregate,fine aggregate,mineral powder and asphalt on the quality and efficiency of asphalt mixture in the process of the mixing,the rolling rule of particles under the action of double horizontal shaft mixer was analyzed by establishing a mixing model. According to the mixing mechanism that asphalt migration occurs on the surface of particles in the process of the rolling,a relational expression between mixing uniformity and particles rolling laps was obtained under the condition that asphalt migration quantity decreased at a certain rate.The rolling relationship between different size particles in the mixing process was calculated through the model of ranging diameter planar circle. Based on the relationship,the technology of phase mixing was put forward. The coarse aggregates,fine aggregates and mineral powder had the same oil film thickness.The double shaft mixer used in laboratory was developed,with the same mixer structure and mixing principle as the mixer used in the practical engineering. The experiment was conducted by dint of AC-16 asphalt mixture. The results show that different particles sizes have different rolling times in the mixing process. The rolling times of the mineral powder are greater than that of fine aggregates,whilst the rolling times of fine aggregates are greater than that of coarse aggregates. Hence,particles with different sizes have different oil film thickness on the surface. The quality of the asphalt mixture and efficiency of mixer can be improved by the phase mixing. Compared with the traditional mixing technology,the amount of asphalt decreases,and the mixing time of the phase mixing can be reduced by 30%.
【Fund】： “十二五”国家科技支撑计划项目(2011BAE28B03);; 中央高校基本科研业务费专项资金项目(2014G3252006);; 内蒙古交通科技项目(NJ-2016-20)
【CateGory Index】： U414
【CateGory Index】： U414