低坍落度路面混凝土振动液化性能研究

发布时间：2018-07-07 08:31

本文选题：滑模摊铺 + 低坍落度路面混凝土　；参考：《交通运输部公路科学研究院》2015年硕士论文

【摘要】：滑模摊铺所用的新拌低坍落度路面混凝土是一种粘稠厚重的固、液、气三相混合物,其振动液化性能是影响滑模摊铺机的施工效率和成形质密混凝土的关键指标。本文以研究新拌低坍落度水泥混凝土材料的振动液化特性为目标,以在混凝土中传递的振动能量为依据,用振动加速度、振动粘度系数、混凝土强度及耐久性等为评价指标,寻找振动液化性能最佳的新拌低坍落度水泥混凝土配合比。首先,利用室内实验室的变频振动台,研究振动台的频率、振幅和振动时间对新拌混凝土振动液化性能的影响,以此标准化滑模摊铺路面混凝土实验所用振动台的参数设定。用混凝土内部采集到的振动加速度有效值,和体积法评价配合比各个参数改变对混凝土振动液化性能的影响。其次,根据振动粘度系数的推导公式,提出振动粘度系数新的测试方法,得到不同时刻点的振动粘度系数。利用室内实验室的高频振动棒,用振动粘度系数评价配合比各个参数改变对混凝土振动液化性能的影响,得到振动粘度系数和与振动棒距离的关系。分析得出两个混凝土振动液化性能的评价指标——振动加速度值和振动粘度系数之间的关系规律。最后,利用缩尺滑模摊铺机,研究在运动荷载作用下新拌水泥混凝土的振动液化性能,并且得到振动能量在混凝土中的传递和衰减规律,优选混凝土配合比。
[Abstract]:The freshly mixed low slump pavement concrete used in sliding form spreading is a thick and thick mixture of solid, liquid and gas. Its vibration liquefaction performance is the key index that affects the construction efficiency of sliding form paver and the forming dense concrete. The aim of this paper is to study the vibration liquefaction characteristics of freshly mixed low slump cement concrete materials. Based on the vibration energy transmitted in concrete, the vibration acceleration, vibration viscosity coefficient, strength and durability of concrete are used as evaluation indexes. To find out the best mix proportion of fresh low slump cement concrete with best vibration liquefaction performance. Firstly, the influence of frequency, amplitude and vibration time on the vibration liquefaction performance of fresh concrete is studied by using the frequency conversion vibration table of indoor laboratory, and the parameter setting of the shaking table used in the concrete experiment of sliding mode paving pavement is standardized according to the influence of frequency, amplitude and vibration time on the vibration liquefaction performance of fresh concrete. The effective values of vibration acceleration collected from the concrete and the volume method were used to evaluate the effect of various parameters of the mix ratio on the vibration liquefaction performance of concrete. Secondly, according to the formula of vibration viscosity coefficient, a new measuring method of vibration viscosity coefficient is put forward, and the vibration viscosity coefficient at different time points is obtained. By using the high frequency vibrating rod in laboratory, the influence of various parameters of the mix ratio on the vibration liquefaction performance of concrete is evaluated by using the vibration viscosity coefficient, and the relation between the vibration viscosity coefficient and the distance between the vibrating rod and the vibration viscosity coefficient is obtained. The relationship between the vibration acceleration value and the vibration viscosity coefficient is obtained, which is the evaluation index of the vibration liquefaction performance of concrete. Finally, the vibration liquefaction performance of fresh cement concrete under the action of moving load is studied by using scale sliding form paver, and the law of vibration energy transfer and attenuation in concrete is obtained, and the concrete mix ratio is optimized.
【学位授予单位】：交通运输部公路科学研究院
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U414

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