▎ 摘　　要

NOVELTY - Method for preparing microwave-expanded graphene material, involves (i) adding 50-100 pts. wt. graphite, 10-40 pts. wt. sodium nitrate and 10-40 pts. wt. potassium permanganate to reaction vessel, dripping 1-5 pts. wt. concentrated sulfuric acid, continuously stirring in an ice water bath, maintaining the temperature of the mixture to less than 50 degrees C, slowly dripping 10-100 pts. wt. deionized water during stirring process, reacting for 3 hours, washing using water when the solution in the reaction vessel is changed from black green to bright yellow, filtering, and drying the graphene precursor under vacuum, and (ii) placing the graphene precursor in a microwave oven, turning on microwave radiation, rapidly expanding the graphene precursor, and turning off the microwave radiation when graphene precursor does not expand anymore to obtain the product. USE - The method is useful for preparing microwave-expanded graphene material is used in concrete materials (all claimed). ADVANTAGE - The method provides microwave-expanded graphene material that has unique physical and chemical properties, improve strength of concrete and performance of concrete materials, and reduces heat of hydration. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) the microwave-expanded graphene material which is prepared by the above-mentioned method; and (2) the use of microwave-expanded graphene material in concrete.