▎ 摘　　要

NOVELTY - Electromagnetic wave absorbing concrete comprises 140-160 kg/m3 water, 1.4-2 kg/m3 nano lithium ferrite/graphene oxide containing polymethyl methacrylate composite absorbing material, 0.8-1.3 kg/m3 nano- beta -manganese oxide/graphene oxide composite absorbing material, 390-430 kg/m3 cement, 25-35 kg/m3 slag powder, 40-60 kg/m3 fly ash, 1.5-2.5 kg/m3 water reducing agent, 550-650 kg/m3 fine aggregate, and 900-1050 kg/m3 gravel. USE - The concrete is useful for electromagnetic wave protection of critical buildings of military and administrative branches, functional building internally provided with a lot of precise electronic instruments, buildings adjacent to radar, microwave base stations and high power wireless communication transmitting stations. ADVANTAGE - The concrete shows a good broadband microwave absorbing performance in a range of 2-18 GHz, preferably 9.8 GHz. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for preparing the electromagnetic wave absorbing concrete, comprising (i) adding water reducing agent into water, and stirring to dissolve at room temperature, (ii) adding nano lithium ferrite/graphene oxide containing polymethyl methacrylate composite absorbing material, slag powder and fly ash into the high speed mixer, and dispersing for 0.5 hours at 240 revolutions/minute, (iii) adding nano- beta -manganese oxide/graphene oxide composite absorbing material into high speed mixer, and dispersing for 1 hour under rotate speed of 280 revolutions/minute, (iv) adding cement, fine aggregate and gravel into a concrete mixer, stirring for 1.5 hours, (v) adding the step (i) aqueous solution within 5-8 minutes , adding into a stirring mill, and continuous stirring for 10-15 minutes to obtain the concrete, and (vi) casting, vibrating and molding using a vibration platform, and curing for 28 days.