Experimental Study On Axial Compression Performance Of Steel Fiber Reclaimed Coarse Aggregate Concrete Short Column With Large Particle Size

Steel fiber large particle size recycled coarse aggregate concrete cement-based composite material is based on traditional engineering cement-based materials,by using large particle size recycled aggregate to replace natural coarse aggregate,adding fly ash and silica fume to replace cement,and A cement-based material that is greener and more environmentally friendly and has higher mechanical properties is prepared by adding appropriate amount of steel fiber.At present,there are few researches on the application of recycled concrete in load-bearing components,and there is a lack of research on large particle size(31.5mm-60mm)recycled aggregate concrete.In this thesis,a combination of experiment and simulation is used to study the axial compression performance of steel fiber large particle size recycled coarse aggregate concrete short columns under monotonic loading,and the effect of wrapping carbon fiber cloth on steel fiber large particle size recycled coarse aggregate The reinforcement of short concrete columns.When designing the mix ratio of steel fiber large particle size recycled coarse aggregate concrete,first of all,this thesis designed and produced 81 sets of 243 large particle size recycled concrete cube test blocks to study its work performance and cube compressive performance,and analyze different water glues.The effect of different recycled aggregate replacement rate,fly ash and silica fume compound content on the work performance and the compressive strength of recycled concrete,and obtain the optimal combination under different recycled coarse aggregate replacement rates.Next,study 3 The working performance and compressive strength of steel fiber large particle size recycled coarse aggregate concrete made with different steel fiber content(1.0%,1.5%,2.0%),and finally choose the best steel fiber content to determine the steel fiber Test mix ratio of large particle size recycled coarse aggregate concrete.According to the component test mix ratio,this thesis designed and produced 4 steel fiber large particle size recycled coarse aggregate concrete short columns,carried out loading tests under monotonic load,and studied the failure mode of the components,load-displacement curve,bearing capacity,etc.Compressive performance indicators,analyzed the influence of different recycled coarse aggregate replacement rates and CFRP cloth constraints on the axial compressive performance of steel fiber large particle size recycled coarse aggregate concrete columns.According to the material mechanical properties measured in the experiment,the ABAQUS software was applied Carry out modeling analysis,and select appropriate material constitutive and model parameters to ensure the accuracy of the model.The main conclusions of this article are as follows:(1)Each test piece shows the characteristics of axial compression failure.The reinforcement method of steel plate at the column end can effectively avoid the occurrence of eccentric compression damage.Compared with ordinary concrete,the steel fiber large particle size recycled coarse aggregate concrete column also has better performance.Good compressive capacity,indicating that steel fiber recycled aggregate concrete is sufficient to meet the requirements of load-bearing capacity in components;(2)Under different recycled aggregate replacement rates,the bearing capacity is slightly lower when the recycled aggregate is 50%,and the compressive performance of the steel fiber large particle size recycled coarse aggregate concrete short column is poor;when the recycled aggregate replacement rate is at 100%,the component has the highest bearing capacity and the best compressive performance;(3)The short column of steel fiber large particle size recycled coarse aggregate concrete constrained by CFRP cloth is adopted.Compared with the non-constrained members,the bearing capacity is significantly improved and the ability to resist deformation is enhanced;(4)Based on the analysis of test data and existing specifications,the formula for calculating the bearing capacity of steel fiber large particle size recycled coarse aggregate concrete columns modified by introducing a concrete reduction factor can more accurately obtain the calculated bearing capacity,and the degree of agreement with the test value Higher,this bearing capacity calculation formula is suitable for calculation of bearing capacity of steel fiber large particle size recycled coarse aggregate concrete columns under different parameters;(5)The bearing capacity value obtained by the numerical model established by the ABAQUS finite element software has a high degree of agreement with the experimental value.The simulated load-displacement curve is similar to the experimental curve,which proves that the simulation has a certain degree of accuracy.