Document Type : Composite Wood Products
Authors
1 Ph.D. Student in wood science and technology, Astara Branch, Islamic Azad University, Astara, Iran
2 Associate Professor, Departman of wood and paper technology, Astara Branch, Islamic Azad University, Astara, Iran
3 Scientific member- Islamic Azad University, Astar Branch
Abstract
Background and Objective: In the present era, technological advancement depends on the progress made in the field of materials and the production of composites has been a significant step towards the evolution of engineering materials. By physically combining two or more materials, not only lighter and stronger material are produced, but such new materials replace the traditional materials. This research aims to compare the mechanical and physical properties of composites coated with small glass beads and shells powder, individually and in mixture, and to select the best sample with lighter specific weight, better strength, and easier installation for building facades.
Materials and Methods: The samples were prepared using beech wood flour, E-grade glass fibers, ortho unsaturated polyester resin matrix, montmorillonite K10 nanoclay, MEPK, 10% cobalt as a constant factor, Caspian Sea rolling shell (Cerastoderma glaucum) powder, and small glass beads as a variable factor. Specimens were made using the hand lay-up method. Variable percentages of glass beads and shells, or a combination of both, were used on the composite as a gel coat. Fifteen composite blocks with dimensions of 20×30×0.7 cm3 were prepared. The edges of the block were then sanded. The blocks were placed in an oven at 120 degrees centigrade for 2 hours, and after cooling, they were weighed and their dimensions were measured, and then cut to the required sizes, and physical and mechanical properties such as water absorption, thickness swelling, bending, tension, impact, and abrasion were measured using ASTM procedures with three replication. Finally, the specific weight was compared according to national building regulations. For data analysis, the SAS9.6 method was used. The validity and reliability of the test were calculated with 99% accuracy based on the test data and reported as an analysis of variance table using SAS software.
.Results: The results of this research showed that the sample made from a combination of nanoclay, beech wood flour, glass fibers, and resin with 30% glass beads coating demonstrate increased impact resistance. The more glass beads were added to the coating, the higher the impact resistance of the composite. With a 30% coating using Caspian Sea rolling shell powder, the composite bending and tension strength increased compared to the control sample. The abrasion rate in composites prepared with 30% glass beads and 30% shell powder was lower after 200 cycles of abrasion compared to other samples. The thickness swelling rate after 48 hours of immersion in water was zero. Although the water absorption rate in the samples was very low, it can be said that samples with a higher amount of shell powder had higher water absorption compared to the control sample. The specific weight of the samples with the dimensions of the 20×30×0.7 cm3 was measured as 1211.9 kg/m³. The highest specific weight in the treatments was related to the sample treated with a 30% glass bead layer coded G180SH0 (p=1240 kg/m³), and the lowest specific weight was related to the untreated control sample coded G0SH0 (p=1192 kg/m³). Meanwhile, the lowest specific weight of stone used for building facades belongs to quartz (p=2000 kg/m³).
Conclusion: In general, it can be mentioned that the composite prepared with a 30% glass bead coating has better quality in terms of abrasion, impact resistance, strength, and no water absorption compared to other samples. From the relative comparison of the specific weight of the samples, it can also be acknowledged that with an increase in specific weight, the impact and bending strength increases, as seen in the G180SH0 sample. Ultimately, the research objective of preparing a strong and lightweight composite for building facade applications was achieved.
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