PURPOSE: To form a non-combustible wave-absorbing wall of high durability and high strength by using a cement wave absorber for high frequency containing ferrite powder having the mean particle diameter of a specific value and less.
CONSTITUTION: A cement wave absorber for high frequency is obtained when 85-40 pts.wt. of ferrite powder having the meant particle diameter of 30μm and less are contained and cured in 15-60 pts.wt. of cement. A high-strength molded body cannot be obtained, if cement is less than 15 pts.wt., and a sufficient wave-absorbing performance cannot be obtained, if ferrite is less than 40 pts.wt. Also, a reinforcing fiber can be contained, because the fiber is excellent in dispersibility and effective in reinforcing a cement-ferrite mortar and gives toughness to the mortar. Further, a water-reducing agent can be contained for improving strength. Thus, when the ferrite powder and cement subjected to grading are used, it is possible to obtain a compact and high-strength molded body also having a wave-absorbing power, to make the molded body into a thin layer and its area larger and to satisfy conditions for a matched thickness of 5-15mm.
TOMITA SHIGEAKI
MATSUBARA YOSHIO
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