Damage patterns of cement concrete with iron tailing under microwave radiation
CHENG Daohua
ZHAO Zhizhong
KANG Xianzhang
CHENG Na
Abstract：To fully leverage the wave-absorbing and heating properties of iron ore tailings and achieve high-value utilization of mining solid waste,this study incorporates iron ore tailings into cement concrete as coarse aggregates to investigate the damage patterns of iron ore tailing concrete under microwave irradiation.X-ray diffraction(XRD)phase analysis is performed on iron ore tailing particles to study the microwave heating mechanism.The temperature changes of iron ore tailing particles and concrete,as well as the ultrasonic pulse velocity(UPV)variations of iron ore tailing concrete before and after microwave irradiation,are analyzed.Scanning electron microscopy(SEM)is employed to observe the surface morphology and microstructure of the concrete before and after irradiation to investigate internal micro-damage.The results indicate that the iron-containing oxides in iron ore tailings possess superior wave-absorbing capabilities.The temperatures of both iron ore tailings and limestone increase with irradiation time,while the heating rate decreases;however,the temperature rise of iron ore tailings is larger than that of limestone.At the same irradiation time,the temperature of iron ore tailing concrete increases with increasing power.The wave-absorbing efficiency is highest at 6 kW.The temperature difference of the specimens before and after irradiation increases linearly at first and then slows down with increasing irradiation time.The UPV of the concrete decreases with increasing irradiation time and power.At the same power,the UPV attenuation rate increases rapidly initially and then slows down with increasing time.Under 0、2、4、6,8 kW power and 0～5 min irradiation,the UPV attenuation rate can reach up to 35.29%.After microwave irradiation,1～3 μm thermal stress cracks are generated in the interfacial transition zone between iron ore tailings and mortar and propagate along the interface.
Keywords：microwave irradiationiron tailingultrasonic wave sound speedcement concrete
Publication Date：2026-01-31
Online Publishing Date：2026-05-22(First online date of this platform, not the publication date of the document)
Pages：9( 87-95 )