Investigation of the properties of gypsum composites produced from cedrus tree (Cedrus libani) and constituents

This study prepared as a master thesis. The cedar tree, which is an important wood raw material in Turkey and its parts (cedar-cone, cedar-bark-, cedar-needle) was utilized to produced test boards with using mineral based (gypsum) adhesive. The physical, mechanical and technological fire insulation and thermal properties of the test boards obtained from six different production conditions were investigated with investigating effects of mixing ratios. The highest rupture strength of cedar wood-bark mixture was observed as 0.48 N/mm2 in Ska5 type boards with the highest cedar bark ratio in the mixture. In the test boards produced with cedar-needle mixture, lower rupture strength values were calculated compare to other type boards. However, in general, the test boards produced from the cedar-needle mixture were calculated to be lower than those produced from the other cedar-wood, bark and cone mixtures. It was assumed that the fibrous properties and density of needles was lower than others. According to the TS EN-ISO 11925-2 standard, the flame spreadpatterns show that it not reaches to a threshold level of 150 mm. As a result of the surface burning experiments, it is generally understood that the test boards that produced without using cedar wood in the mixtures, showapproximately 10-25oC higher heat conductivity. However, the lowest heat conductance was determined as 109.4oC in SI2 type board and 143.8oC in KaKo3 type board. No correlation was found between the mass loss and the heat permeability of the test boards produced with using cedar wood and its parts.