Mechanical Response Analysis Of Voids Beneath Concrete Slabs Precast Concrete Pavement

Precast Concrete Pavement is a new and sustainable environmental protection concrete pavement system.Its characteristics are as follows: Concrete slabs can be produced in factories all the time without the influence of climate,and the quality of concrete will not be very different and easily guaranteed;the construction speed will be fast,the construction period will not be delayed,and the road will be opened after the completion of paving;the damage will be easy to dismantle and repair.Because the domestic research on the pavement directly using prefabricated pavement slab is relatively few,the pavement structure design method which can guide the actual design is not mature enough.Therefore,this paper will analyze the mechanical response of the assembled cement concrete,and study the mechanical mechanism of the floor void damage,so as to provide a theoretical reference for engineering practice,and has a certain theoretical support and application value.Firstly,it expounds the causes of self-destruction of common pavement slabs,such as surface cracks and penetrating cracks,and the causes of damage of pavement prefabricated slabs in the process of transportation and assembly.The common pavement diseases at the joints of prefabricated cement concrete pavement face slabs are the damage of staggered platform,mud and joint materials,and the void at the bottom of the slab.The void at the bottom of the slab is the main cause of the pavement damage,and leads to the rapid damage of the pavement slab.Most other pavement diseases often accompany with the void phenomenon at the bottom of the pavement slab.Therefore,in the following chapters,mechanics is adopted.Establishment of a model of void of assembled cement concrete slab from the angle of responseThen,according to the analysis theory of finite element method and with the help of general finite element software,the model of assembled cement concrete pavement is established.The influence of different surface thickness and elastic modulus,different base thickness and elastic modulus on mechanical response of assembled cement concrete pavement is analyzed,and the optimum parameter structure range is obtained.At the same time,in order to make the prefabricated plate meet its smoothness requirements,find the optimum range of elastic modulus of base leveling layer material,and get the range of elastic modulus of leveling layer material in 20-25 GPa is the most advantageous for structural stress.Finally,aiming at the main diseases of assembled cement concrete pavement,the phenomenon of void at the bottom of slab.Using general finite element software to analyze the void condition of the bottom of assembled cement concrete pavement slab.It is found that the effect of void depth on surface stress and maximum vertical deflection is not significant whether the void is in the corner or in the plate.With the increase of the void radius in the plate,the maximum stress and the maximum vertical deflection of the surface layer increase continuously;with the increase of the void radius at the corner of the plate,the maximum stress and the maximum vertical deflection of the surface layer increase continuously,and the stress and deflection of the void at the corner of the plate are more disadvantageous than that of the void in the plate when the void radius is the same.