采用立轴行星式搅拌机,开展了基于新型搅拌控制模式的混凝土试验,监测分析了典型铁路混凝土的主轴转矩和湿度变化规律,研究了搅拌时间、搅拌转速对不同强度等级混凝土抗压强度的影响,探究了混凝土自动搅拌调控方法的可行性.结果表明:混凝土抗压强度随搅拌时间延长先增大然后趋于平缓;相同搅拌速度下搅拌时间越长,混凝土的早期抗压强度提高越显著;搅拌时间达到临界值后,继续延长搅拌时间,混凝土抗压强度基本不变;主轴转矩和湿度对不同强度等级混凝土搅拌状态的响应程度有所区别,主轴转矩更适用于水胶比较低(C50、C60)混凝土状态的监测,湿度更适用于水胶比较高(C30、C40)混凝土状态的监测;通过采用基于主轴转矩和湿度参数监测的分级加水或加减水剂的自动搅拌调控方法,可实现混凝土拌和物状态的自动调控.
This study employed a vertical-axis planetary mixer with an innovative mixing control mode to conduct concrete experiments.The research involved monitoring and analyzing main shaft torque and humidity variations in typical railway concrete.The impact of mixing time and speed on the compressive strength of concrete across different strength grades was examined.Additionally,the feasibility of automatic mixing control methods was explored.Results indicate that compressive strength initially increases with extended mixing time,followed by a plateau.Longer mixing times under the same speed result in a more pronounced early increase in compressive strength.Beyond a critical mixing time,further extension has minimal effect.The response of main shaft torque and humidity varies with different concrete strength grades,with main shaft torque suitable for monitoring low water-cement ratio(C50,C60)concrete states,and humidity for high water-cement ratio(C30,C40)concrete states.The study proposes an automatic mixing control method based on monitoring main shaft torque and humidity parameters,enabling the automatic regulation of concrete mixing and material states.