Temperature Field And Stress Of CRTS? Slab Ballastless Track In The Initial Pouring Stage Of Self-compacting Concrete

The temperature of the early age concrete structure will increase rapidly due to the hydration heat of the cement,and a large stress will be generated inside the structure during the subsequent cooling process.If the stress exceeds the tensile strength of the structure,early cracks will be formed inside the structure,which will affect the durability of the structure.As a layered concrete structure,it is not clear how the temperature of the CRTS? ballastless track changes during the initial stage of self-compacting concrete pouring and whether the self-compacting concrete layer stress exceeds its tensile strength during actual construction.Therefore,it is necessary to study the temperature field and stress of CRTS? ballastless track in the initial stage of self-compacting concrete pouring.Firstly,the self-compacting concrete perfusion test of CRTS? ballastless track is carried out,where the temperature of track structure in the initial pouring stage is monitored in real time and the corresponding meteorological data is collected.The measured data is used to analyze the change of the temperature field of the track structure in the initial pouring stage.Secondly,the heat transfer mechanism of the ballastless track is analyzed,and the heat conduction control equation with considering of heat source is introduced.The temperature field model with the hydration heat generation of the self-compacting concrete is established,and then the meteorological data of the above test is input to calculate the temperature field of track structure,which is compared with the measured values,and the stress of the concrete layer is discussed.The internal simple stress model of concrete considering the self-compacting concrete shrinkage and temperature is proposed.Finally,the temperature field model is used to calculate and analyze the temperature field of CRTS? ballastless track in the initial pouring stage of self-compacting concrete in summer and winter.The stress in the initial pouring stage is calculated based on the temperature of the self-compacting concrete and then compared with the tensile strength to provide reference for the construction of CRTS? ballastless track.