Fracture behavior of concrete coarse aggregates under microwave irradiation influenced by mineral components

Abstract Significant damage of some coarse aggregates due to microwave irradiation is neglected by most previous studies on microwave-assisted concrete recycling technique. Fracture behavior of commonly used coarse aggregates: granite and basalt were investigated by microwave heating tests. Heating rate of aggregates’ mineral components was tested respectively. Ilmenite was heated rapidly while other minerals were heated tardily. Larger temperature gradient was generated in basalt because of more ilmenite content to induce fracture, granite was not fractured yet. Most initial cracks in basalt extended along clockwise angle in Mode Ⅰ. Fracture of basalt occurred with more damage at higher power level.