Investigation On Influence Of Strengthening Of Coarse Aggregate On Performance Of Recycled Concrete

At present,due to rapid economic development,a large number of buildings have been demolished,resulting in environmental pollution and lack of resources.The construction waste is recycled and reused,and recycled coarse aggregate is used as the raw material of concrete to make recycled concrete,which can turn waste into treasure,which can save resources and protect the environment.However,in the preparation process of coarse aggregate,due to the limitations of current technology,the strengthened coarse aggregate has poor quality and low strength,which will prevent the recycling of recycled concrete from being widely used in actual projects.The microwave-assisted mechanical stren gthening aggregate technology strengthens the recycled coarse aggregate,greatly improves the performance of the aggregate,and has high research significance and promotion value.This paper uses microwave technology to strengthen recycled aggregates,conducts macroscopic and microscopic experimental research on the produced recycled concrete,and analyzes its mechanical properties and strengthening mechanism according to the test results.The main conclusions are as follows:(1)The waste concrete test block is irradiated with different microwave powers to find the best power irradiation range;the digital infrared thermal imaging camera captures the surface temperature distribution of the old cement mortar and coarse aggregate of the waste concrete after the microwave irradiation;the natural aggregate,Physical performance tests of unreinforced aggregates and reinforced aggregates were carried out separately,and the superiority of microwave-assisted mechanically reinforced aggregates was demonstrated through comparative analysis;(2)Prepare ordinary concrete,reinforced recycled concrete,and unreinforced recycled concrete with C30 strength grades through different types of aggregates produced,and combine the replacement rate and age as variables to perform cubic compression on the specimens,Prism body compression and split tensile test,according to the test results,comparative analysis of different coarse aggregates on the damage form,compressive strength,split tensile strength,elastic modulus and stress-strain of recycled concrete.The law of change further illustrates the generalizability of the process of strengthening recycled concrete;(3)Combined with the scanning electron microscope test,analyze the structure of the interface transition zone of different coarse aggregates,the damage degree of the microwave intensified coarse aggregate,and the analysis of cement hydration reaction from a microscopic point of view.The analysis is compared with the macroscopic experiment,which shows the feasibility of microwave-assisted mechanical strengthening of aggregates.