Study On The Axial Compressive Properties Of Circular Steel Tubular Ceramic Recycled Aggregate Concrete Short Columns

The research on the safe disposal and comprehensive utilization of waste ceramics has become a hot topic both domestically and internationally.In order to better utilize waste ceramics,it is proposed to replace coarse and fine aggregates with crushed waste ceramics to prepare ceramic recycled aggregate concrete,which is then poured into steel pipes to form a composite structure of steel pipe ceramic aggregate concrete.Through the constraint effect of steel pipes,the performance of ceramic aggregate concrete is further improved.In view of this,this article studies the compressive strength and elastic modulus of recycled ceramic concrete specimens,conducts axial compression tests and finite element simulation analysis on steel tube ceramic recycled aggregate concrete short columns,explores the mechanical properties and feasibility of steel tube ceramic recycled aggregate concrete short columns,and provides reference for engineering practice.The main work of this article is as follows:(1)Tested the material properties of ceramic recycled coarse and fine aggregates and compared them with natural aggregates.Design ceramic recycled aggregate concrete mix proportions with different aggregate replacement rates based on the different replacement rates of ceramic coarse and fine aggregates.20 sets of 120 ceramic recycled aggregate concrete cubes with different aggregate replacement rates were made for 7-day and 28-day compressive strength testing,and 12 concrete cubes without ceramic aggregates were made for comparison;Made the same number of prism specimens with different mix ratios for testing the elastic modulus of concrete.The experimental results indicate that concrete mixed with ceramic coarse aggregate requires the addition of additional water to achieve workability similar to traditional concrete;The mechanical properties of concrete made by completely replacing natural river sand with ceramic fine aggregate are slightly lower than traditional concrete.In the case of completely replacing ceramic fine aggregate,an increase in the replacement rate of ceramic coarse aggregate will significantly reduce the compressive strength and elastic modulus of concrete;The shear strength of ceramic coarse aggregate is a decisive factor in the strength of concrete.When the replacement rate of coarse aggregate exceeds 50%,it will cause shear failure due to the crushing of ceramic coarse aggregate,and the compressive strength and elastic modulus cannot meet the requirements of C40 concrete strength grade.(2)21 circular steel tube ceramic recycled aggregate concrete short columns were made for axial compression tests to observe the failure mode of circular steel tube ceramic recycled aggregate concrete short columns under axial force,analyze the stress process of the short columns under axial force,and explore the effects of different ceramic aggregate substitution rates and steel content on their ultimate bearing capacity,load displacement curves,and stress-strain curves.The experimental results show that traditional circular steel tube concrete short columns and circular steel tube ceramic recycled aggregate concrete short columns have similar stress processes and failure forms.The steel tube concrete in the experiment exhibits four types of failure modes: shear failure,waist drum failure,longitudinal compression failure,and longitudinal cracking failure of the steel tube wall,which is related to the constraint effect of the steel tube on the concrete.(3)Using the finite element analysis software ABAQUS,a test model of circular steel tube ceramic recycled aggregate concrete short columns was established to simulate its axial compression test.The stress mechanism of steel tube ceramic recycled aggregate concrete short columns under axial compression was analyzed and the ultimate bearing capacity was calculated.Through analysis and comparison of test results,it is found that the circular steel tube ceramic recycled fine aggregate concrete short columns poured with ceramic fine aggregate instead of natural river sand have similar mechanical properties to the traditional steel tube concrete columns.In the case of complete replacement of ceramic fine aggregates,with the development of ceramics...