Document Type : Research Paper
Authors
1 Assistant Prof, Dep. of Wood Science and Engineering, Technical Faculty of No. 2, Mazandaran Branch, Technical and Vocational University (TVU), Sari, Iran
2 Wood and Forest Products Science Research Division, Research Institute of Forests and Rangelands, Agricultural Research Education and Extension Organization (AREEO) P.O. Box 13185-116, Tehran, Iran
3 B.Sc, Student, Dep. of Wood Science and Engineering, Technical Faculty of No. 2, Mazandaran Branch, Technical and Vocational University (TVU), Sari, Iran
Abstract
In this study, the possibility of making gypsum-based boards from rice straw chips with different levels was investigated. Variable factors in this study were considered in nano at three levels of 0, 3 and 7% and also the ratio of mixing rice straw to gypsum at three levels ( 5:95 , 10:90 , 15: 85 %). Thus, with the consideration of nine treatments, a total of 27 laboratory boards were constructed. The specific mass of the first target 1.10 gr/cm3 was considered. Mechanical and physical properties of composites include modulus of rupture, modulus of elasticity, internal bonding, water absorption after 2 and 24 hours of immersion, and density of boards according to standard (DIN-EN-634) and fire resistance (weight loss percentage) they were measured according to a standard ISO-11925. In order to investigate the common chapter of rice straw and gypsum as well as the distribution of nano-wollastonite, microscopic images (SEM) of the fracture surface of the samples were prepared and the results showed that the composites made with nano-wollastonite had higher mechanical and physical strengths. Microscopic imaging (SEM) showed that the boards made with 7% nano had stronger internal connections and created a uniform structure. In this study, composites made of 7% nano wollastonite with 5% rice straw were selected as the optimal treatment.
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