Electromagnetic radiation has become a great threat to human health. In this paper, ferrite and graphite were main absorbing agent, which were prepared to a new type of anti-electromagnetic radiation gypsum board. The results show that the microwave absorbing properties of ferrite/graphite mixed are better than with ferrite or graphite single-agent mixed. The gypsum board with the graphite content of 5wt% and the ferrite content of 25wt% has the best absorbing performance, The effective band width less than-5dB of the samples is 7.1311GHz, and the maximum absorption peak-18.467dB.

Silica aerogel is a lightweight nanomaterial,which was originally applied to aerospace and military fields. With the optimization and improvement of silica aerogel production process, it has more applications in the field of energy saving, environmental protection, building material etc. This paper introduces some kinds of drying processes, some methods had been used in the production, while the others are under the consideration.

There were many problems when natural flake graphite was used in gypsum as an absorbing agent, such as absorbing large amount of water, a poor interfacial compatibility and so on. In this paper, polycarboxylate-based water reducer and AES (sodium alcohol ether sulphate) are used to modify graphite-gypsum system. The results show that both agents are effective to improve the properties of gypsum system and the former is best. Compared with the sample without any reagents, polycarboxylate-based water reducer can reduce the water-solid ratio from 1.1 to 0.9, increase the compressive strength from 0.106Mpa to 0.701Mpa and the flexural strength form 0.064Mpa to 0.312Mpa.

In order to improve the durability of the wood fiber reinforced external wall board, silica fume, a kind of inorganic silica material was added in the board. The properties of the boards containing different amount of silica fume were studied. The durability was effectively characterized by determining the fracture work and bending strength after wetting-drying cycles test of the board. The results showed that the fracture work and bending strength of the board obviously increased when the proportion of silica fume and cement was 1:9~1:3.

Asbestos is used as reinforcing fiber in nearly all the current external wall board manufacturing process, but it has harmful effects on the human body. In this paper, composite-fiber reinforced external wall board without asbestos was successfully prepared using plant fibers as reinforcing material instead of asbestos by compression molding. Effect of the content of wood fiber, wood powder, quartz sand and water on the density and mechanical properties of the board were studied in this work. Besides, the optimized preparation method for composite-fiber reinforced external wall board without asbestos was achieved.