Experimental Study On Dynamic Mechanical Properties Of Recycled Concrete Under Impact Load

With the development of society and the acceleration of urbanization,the concrete used in engineering construction consumes a lot of natural resources.At the same time,the demolition of old buildings has produced a large amount of waste concrete,which has adverse effects on environmental and resource issues.The use of recycled concrete not only protects natural resources,but also solves the environmental problems caused by abandoned concrete.It has become a research hotspot.Impact collisions occur in the engineering structure,such as cars,ships and other collisions with surrounding buildings,bridges,etc.,severely damage the structure,causing casualties and economic losses.Therefore,the study of dynamic mechanical properties of recycled concrete under impact load is particularly important.The paper mainly studies the dynamic mechanical properties of recycled concrete under impact loading.The experiment studied the effects of different treatment methods of recycled aggregates,different replacement rates of recycled aggregates and different impact pressures on the dynamic mechanical properties of recycled concrete,and combined with the energy dissipation characteristics in the impact process.The test coarse aggregate is made of natural aggregate(N),original recycled aggregate(R1)and cement wrap carbonized and treated recycled aggregate(R2).The replacement ratio of recycled aggregate is 05 30%,70%and 100%.Four kinds,the impact pressure is 0.4MPa,0.6MPa and 0.8MPa.The test results show that under the same impact pressure,the dynamic compressive strength of recycled concrete decreases with the increase of the replacement rate of recycled aggregate.When the impact pressure is 0.4MPa,0.6MPa and 0.8MPa,the dynamic compressive strength of recycled concrete with R1 and R2 substitution rate of 30%is 29.2MPa,34.9MPa.40.9MPa and 31.1 MPa.37.8MPa.42.2MPa.Compared with the dynamic compressive strength of ordinary concrete,they are reduced by 11.8%,12.8%,10.7%,and 6.0%,5.5%,7.9%;But the dynamic compressive strength of R2 recycled concrete is higher than that of R1 recycled concrete,they increased by 6.5%,8.3%and 3.2%The results of energy dissipation characteristics of recycled concrete under different impact pressures show that with the increase of impact pressure,the incident energy,absorbed energy and energy consumption of test block crushing of recycled concrete are also increasing.According to the experimental data,the incident energy and the absorbed energy and the energy density of the test block are respectively fitted to each other,and a linear fitting equation with good correlation is established.Figure[35] Table[8] Reference[70]...