Research On The Workablility Characterization And Control Of The Sliding Mode Paving Concrete

This paper studies the air entraining theory and current situation of the development of the air-entraining agent,proposed compound is the future development direction of air-entraining agent: it is maybe to obtain desired air entraining performance and overcome the defect of a single species by compounding different surface active agent.This paper expounds the current status of concrete workability test method,domestic main testing methods and its limitations,According to the unique requirements of slip-form paving technical workability of concrete,puts forward a new way of workability test method-the quantity of concrete liquefied slurry.Characterizate the formwork erection performance and the vibration compaction performance by slump and the quantity of liquefied slurry,the results showed that different air-entraining agents impacts the workability differently even with the same air content,the formwork erection shows great interdependency with the concrete's slump.The method proposed in this paper has a very good effect which can control the concrete's vibration compaction performance very well,aslo can be used to evaluate the workability difference between the same slump concrete.In order to satisfy the coordination of the slip-form paving pavement cement concrete performance between formwork erection and vibration compaction,using orthogonal test and extreme difference analysis,variance analysis to design a new type composite air-entraining agent.According to the actual circumstance of sliding mode paving construction technology and technical requirements,proposed using the slump,the quantity of slurry,high frequency vibrating intensity as control index,the results showed that: the new type of air-entraining agent optimal mixture ratio: X component 10,Y component 4,1.43 a Z component;The air-entraining agent Less influence on the concrete strength loss,and in the process of slip-form paving construction,combining the model of concrete performance and vibration compaction performance,has the very good application effect.Combining with the characteristics of sliding mode paving construction technology,research the impact of high frequency vibrating on concrete's air-content,pore structure,rheological property,demonstrates the possibility of using cement mortar workability characterization of concrete workability,and in the process of high frequency vibrating pore structure change influence on rheological property of concrete study,for the new development of air-entraining agent provides the theoretical basis,the results show that : high frequency vibration will lower the air content of concrete,and the result varies in different air-entraining agents;The effect of high frequency vibration on the spacing factor is not obvious,but it will reduce the diameter of the pore;The yield stress and plastic viscosity of cement mortar are increased by high frequency vibration.To the air-entraining agent used in this paper,Reduction of the average pore diameter can make the air-entraining cement mortar plastic viscosity and yield stress increased,its mechanism is to achieve the coordination of the concrete formwork erection performance and the vibration compacting performance through the dynamic change of pore structure during the high frequency vibration.