| Faced with the increasing emissions of solid waste from circulating fluidized bed boilers is aggravated,the recycling of desulfurization slag needs to be solved urgently.In this experiment,the steel tube of self-compacting concrete blended with modified circulating fluidized bed bottom ashes are manufactured.The new type of material composite structure is obtained,in addition to the self-compacting properties,the concrete also has a unique micro-expansion characteristics.The structure itself has the advantages of ordinary concrete filled steel tubes,that is,the overall stability and the compressive strength properties are high,self-compacting properties are also available.Compared with ordinary concrete filled steel tube,it can save vibration time and greatly improve construction progress.When the concrete filled steel tube structure is loaded,the force is passed to the steel tube first,then passed to the concrete by the bond between the steel tube and concrete,so that the concrete is in the compression state,the two parties bear the force together.Therefore,it is great significance to study the bond between the steel tube and the concrete.At present,a lot of research has been done on the interface bonding of ordinary concrete filled steel tube at home and abroad.However,for the study of the desulfurization slag material itself,no one has made it into high-performance concrete and studied its interface bonding performance.In this article,interface bonding performance of 16 steel tube specimens were evaluated subjected to the amount of desulfurization slag,water cement ratio and bond length.The conclusions are as follows:(1)The test verifies that the steel tube of self-compacting concrete blended with circulating fluidized bed bottom ashes is the same as that of ordinary steel tube concrete that on the surface of steel tube,the stress is distributed exponentially along the length direction.(2)According to the test data,the "load-slip" curve of the structural specimens are obtained and its variation law is analyzed.At the same time,the ultimate bond load,theaverage bond strength and the ultimate relative slip value on the interface of the self compacting concrete filled steel tube are calculated.(3)The experimental study on the interface bonding of self-compacting concrete blended with the different amount of desulphurized slag shows that bond load increases by7% with the content of 10% compared with that of the undoped specimens;bond load increases by 18% with the content of 30% compared with that of the undoped specimens;bond load increases by 40% with the content of 50% compared with that of the undoped specimens,but limiting relative slip value decreases with the increase of the content of desulphurization slag.(4)Based on the three factors which the dosage of desulphurization slag,water cement ratio and bond length,the experimental data show that the interface bonding performance of concrete filled steel tube increases with increasing water cement ratio when the amount of desulphurization slag is certain;the interface bonding performance of the self compacting concrete filled steel tube blended with desulphurization slag increases with increasing bond length when the amount of desulphurization slag and water cement ratio are certain.(5)The Finite element simulation of the self compacting concrete filled steel tube blended with desulphurization slag is established by ANSYS software,according to the experimental data,the constitutive relationship and basic properties of the material are determined,and the spring element is used to simulate the interface bonding of the member.The results show that the calculated results agree well with the test results,and the error bettween ultimate bond load obtained by the finite element method and experimental results is within the permissible range. |
