Experimental Study On Performance Degradation Of Concrete-filled GFRP Tube Short Column Under Alkaline Action

As a new type of material,GFRP material has the advantages of light weight,high strength,and good corrosion resistance.Its application and research have become a hot spot in the civil engineering industry at home and abroad.The mechanical degradation of concrete-filled GFRP tube short columns subjected to alkali is related to the safety performance and normal use of GFRP reinforced structures,which is the key to the design calculation and engineering application of concrete-filled GFRP tube short columns.Through the core concrete defect detection,ultimate bearing capacity and strain change analysis of concrete-filled GFRP tube short columns with a height of300 mm,an inner diameter of 100 mm and a wall thickness of 3mm,Study on the degradation behavior of concrete-filled GFRP tube short columns under different corrosion states and different corrosion cycles in alkaline environment.The main conclusions are as follows: Alkali solution has a strong corrosive effect on concrete-filled GFRP tube short columns.With the increase of the corrosion cycle,the ultimate bearing capacity and ultimate strain of concrete-filled GFRP tube short columns gradually decrease in two states;Under the same cycle,the corrosion of concrete-filled GFRP tube short columns under static conditions is more severe than that under dry and wet cycling conditions.The ultimate bearing capacity of the specimens is lower than the ultimate bearing capacity of the specimens under dry and wet cycling conditions.The average strain is lower than the average axial and annular ultimate strain of the test piece in the dry and wet cycle state;Corrosion in the static state has a greater impact on the interior of the core concrete of the test specimen,resulting in more serious defects.