Study On Mechanical Properties Degradation Law Of Reinforced Concrete Columns Under The Coupling Action Of Coal Mine Environment And Load

Under the coupling effect of coal mine environment and load,the reinforced concrete columns appeare different degree of damage and deterioration,severely damage in part of structure.The columns are vertical load-bearing components.The destruction of the columns are often more serious than the consequences of other components.To grasp the mechanical properties degradation law of the reinforced concrete columns,based on the environment of coal mine and subject of previous research achievements,component and simulation environment are improved.Adding load coupling factors of damage and degradation improves environment The experimental study on reinforced concrete columns of degradation,damage and degradation are carried out,main conclusions are as follows:1.The compressive strength and the elastic modulus of the degradation of concrete specimen were obtained.Compressive strength and elastic modulus of concrete specimens increased gradually in the first two period.From three to six period,the compressive strength and the elastic modulus of specimen gradually decreased,With the increase of the period,the damage and degradation in the column samples increased and the products of degradation increased gradually in the microstructure.The compressive strength of the cores of columns tended to decrease.The performance of columns of damage and degradation were more obvious.2.The degradation behavior of corrosion of the steel bar was obtained.In the first three period,with the increase of corrosion rate,the yield strength and ultimate strength of the steel bar tended to decrease,but the trend of decrease was relatively slow.With the increase of period,the corrosion rate of steel bar gradually increased.But the degree of increase was slowly,the corrosion rate of columns of damage and degradation increased rapidly.3.The development and failure characteristics of the test process were obtained.The carrying capacity of columns of degradation increased slightly in the first period.With the increase of period,the capacity of columns of degradation were reduced.And the carrying capacity of columns of damage and degradation were reduced in three period.The theoretical calculation formula of the bearing capacity of columns in the initial stage were obtained.4.The degradation of the bearing capacity of columns was obtained.The morphological development and the damage morphology of columns of degradation,damage and degradation was not very different.The differences were mainly manifested in the development of fractures and the failure modes of the compression zone.With the increase of the period,the speed of crack development in the loading process was accelerated,the width of the crack increasesd,and the number of cracks in columns decreased,and the form of the compression zone was more prominent.The performance of columns of damage and degradation were more obvious.5.The degradation behavior of the deformation ability of columns were obtained.With the increase of the corrosion period,the deformation ability of columns decreased,the deformation ability of columns of damage and degradation were more obvious.