| 1. |
- Adamopoulos, Stergios, et al.
(författare)
-
Effect of laser drilling on mechanical properties of fir (Abies borisii regis) and spruce (Picea excelsa) wood
- 2014
-
Ingår i: Wood Structure, Properties and Quality – 2014. - : Moscow State University Press. - 9785813506253 ; , s. 7-12
-
Konferensbidrag (refereegranskat)abstract
- Fir and spruce wood specimens, 2×2 cm in cross section and 34 cm long, were pre-pared with true radial and tangential surfaces. All lateral surfaces of the wood specimens were drilled by laser beams to a depth of 0,4 cm (1/5 of specimen thickness) with two drilling pat-terns (distance between holes 1 × 1 cm and 1 × 2 cm). After drilling, static bending (MOR, MOE), axial compression strength and toughness were determined and compared with non-drilled control specimens. The effects of the two laser drilling patterns on mechanical proper-ties of fir and spruce wood specimens were measured and assessed. The results showed that the two drilling patterns created by laser beams on all lateral surfaces of fir and spruce wood specimens at 0,4 mm depth did not practically affect the mechanical properties of wood.
|
|
| 2. |
- Foti, Dafni, et al.
(författare)
-
Compression strength properties of gypsum matrix composites with recovered fibrous scrap materials from post-consumer tyres
- 2020
-
Ingår i: International journal of materials & product technology. - : InderScience Publishers. - 0268-1900 .- 1741-5209. ; 61:1, s. 53-67
-
Tidskriftsartikel (refereegranskat)abstract
- Gypsum-based experimental cylindrical samples were prepared using three fractions of recycling tyre 'fluff' material ('as received', fractions >4 mm and <4 mm) in three proportions (10%, 20%, 30%) by weight. The density values of the samples were found to decrease with increasing the proportion of 'fluff' material incorporated in gypsum. Compressive strength and density of cylindrical samples were positively correlated for all combinations, and their relationships were found statistically significant. Compressive strength values ranged between 1.00-7.64 N/mm(2) for the 'fluff' fraction <4 mm, where they were the highest, 0.37-1.59 N/mm(2) for the 'fluff' fraction >4 mm, where they were the lowest, and between 0.39-4.22 N/mm(2) for the 'fluff' fraction 'as received' during recycling, where they were intermediate. Calculations of the required compressive strength in the case of using 'gypsum-fluff' building bricks in interior walls showed that all 'gypsum-fluff' combinations exhibited the adequate strength to perform successfully.
|
|
| 3. |
- Foti, Dafni, et al.
(författare)
-
Microstructure and compressive strength of gypsum-bonded composites with papers, paperboards and Tetra Pak recycled materials
- 2019
-
Ingår i: Journal of Wood Science. - : Springer. - 1435-0211 .- 1611-4663. ; 65:1, s. 1-8
-
Tidskriftsartikel (refereegranskat)abstract
- The incorporation of recycled papers, paperboards and Tetra Pak as filling materials in brittle matrices presents aninteresting approach in the utilization of waste materials for building construction. This paper examines the compressivestrength and microstructure of gypsum-bonded wastepaper-based composites. Recycled wastepaper of varioustypes (office paper, magazine paper and newspaper), cardboards, paper boxes and Tetra Pak were shredded to shortlength strips of about 4 × 18 mm. The shredded materials were used as filling materials in natural gypsum in a ratioof 1:3 (v/v), and water was added to the mix. The paste was formed in cylindrical samples measuring 10 cm in lengthand 5 cm in diameter. Seven different types of composites were produced depending on the material used. Thecomposite products with newspaper and magazine paper had significantly lower density and compressive strength(p < 0.05) than the others. However, the differences were small to have any practical importance. The density valuesranged between 1.26 and 1.34 g/cm3, and compressive strength was the lowest (4.48 N/mm2) in the gypsum–magazinepaper composites and the highest (6.46 N/mm2) in the gypsum–Tetra Pak I composites. Since the samplesproduced in this study exhibited adequate compressive strength, the products could be suitable for such applicationsas interior walls in building constructions. Scanning electron microscopy (SEM) examination of the fractured surfacesrevealed needle-like structures of gypsite crystals surrounding the fibers, which indicates good adhesion between thehydrophobic matrix and lignocellulosic fibers.
|
|
| 4. |
- Karastergiou, Sotirios, et al.
(författare)
-
Impregnation of fir (Abies borisii regis) and spruce (Picea excelsa) wood with rape oil and CCB preservative
- 2014
-
Ingår i: Wood Structure, Properties and Quality – 2014. - : Moscow State University Press. - 9785813506253 ; , s. 77-82
-
Konferensbidrag (refereegranskat)abstract
- The objective of this study was to examine the retention (kg/m³) and the penetration depth (mm) as well as the impregnated area of cross sections (%) along the hole length, in fir (Abies borisii regis) and spruce (Picea excelsa) wood, after preservative treatment with rape oil and CCB preservative (3,2 %). The wood specimens (5×5 cm or 10×10cm in cross section and 40 cm long) with true radial and tangential surfaces, were treated with the full cell pro-cess. In order to determine the effect of direction (axial, lateral/radial or tangential) on pene-tration of rape oil and CCB preservative, the surfaces of the specimens were coated (laterally in all surfaces and in cross sections, respectively). Retention of rape oil ranged between 21,06 and 78,51 kg/m3 in fir specimens and between 11,20 and 90,32 kg/m3 in spruce specimens, while retention of CCB preservatives fluctuated between 1,68 and 10,05 kg/m3 in fir and be-tween 1,86 and 6,80 kg/m3 in spruce specimens. Penetration depth in all directions as well as impregnated area of cross sections of wood specimens were found to be lower in spruce than in fir for rape oil and, in most cases, for CCB preservative tested. The general conclusion is that both species are difficult to impregnation, but fir is more permeable than spruce.
|
|
| 5. |
- Voulgaridis, Elias, et al.
(författare)
-
Effect of laser drilling on impregnability of fir (Abies borisii regis) and spruce (Picea excelsa) wood
- 2014
-
Ingår i: Wood Structure, Properties and Quality – 2014. - : Moscow State University Press. - 9785813506253 ; , s. 51-56
-
Konferensbidrag (refereegranskat)abstract
- Fir and spruce wood specimens, 2×2 cm in cross section and 34 cm long, were pre-pared with true radial and tangential surfaces. All lateral surfaces of the wood specimens were drilled by laser beams to a depth of 0,4 cm (1/5 of specimen thickness) with two drilling patterns (distance between holes 1×1 cm and 1×2 cm) in order to improve the wood permea-bility of these refractory to impregnation species. After drilling and assessing the drilling ef-fect on mechanical properties of wood, wood specimens, 10 cm long, were impregnated with oil and CCB preservatives by using vacuum (0,6 mmHg) and pressure (1,5 bar) for 15 minutes and 30 minutes, respectively. The effects of the two laser drilling patterns on impreg-nability of fir and spruce wood specimens were measured and assessed. The results showed that both drilling patterns created by laser beams on all lateral surfaces of fir and spruce wood specimens at 0,4 mm depth improved the retention and penetration of preservatives in fir and spruce wood specimens. This effect was more pronounced in fir than in spruce. Between the two drilling patterns, the pattern with distances between holes 1×1 cm was more effective than that with distances 1×2 cm, in both species tested.
|
|
| 6. |
- Voulgaridis, Elias, et al.
(författare)
-
Properties of gypsum bonded solid bricks manufactured with recovered wood and rubber
- 2013
-
Ingår i: Annual Meeting Prosylva Europe and 16th Panhellenic Forestry Conference , 6-9 October 2013, Thessaloniki, Greece.
-
Konferensbidrag (refereegranskat)abstract
- Utilization of recovered wood fromparticleboard production residues and rubber from waste tires in the manufacture of solid bricks was investigated, using gypsum as bonding media. The manufacturing parameters were: small and large rubber and wood particles, different gypsum/wood/rubber ratios for each fraction (small, large), and different gypsum/water ratios. Cylindrical samples, produced by pouring the mixtures into cylindrical molds, were used for testing compressive strength, thermal conductivity and sound absorption according to standard methods.Compressive strength of all gypsum bonded wood and rubber samples was much lower than the controls, e.g. pure gypsum samples. It was found that the wood samplesand the larger fractions (both rubber and wood) were superior in strength than the rubber samples and small fractions, respectively. A maximum proportion25% of wood or rubber as well the use of reclaimed fibrous materials in the manufacture of samples would probably ensure an acceptable compressive strength. No differences were found among the wood/rubber typesfor thermal conductivity, while particle size and proportion of the materials had no effect. Samples with small wood and rubber particles at the lower proportion (25%) were similar in their sound absorption behaviour.
|
|
| 7. |
- Voulgaridis, Elias, et al.
(författare)
-
ΠΑΡΑΓΩΓΗ ΚΑΙ ΙΔΙΟΤΗΤΕΣ ΠΕΙΡΑΜΑΤΙΚΩΝ ΠΛΙΝΘΩΝ ΕΣΩΤΕΡΙΚΗΣ ΤΟΙΧΟΠΟΙΙΑΣ ΑΠΟ ΓΥΨΟ ΚΑΙ ΑΝΑΚΥΚΛΟΥΜΕΝΑ ΥΛΙΚΑ ΞΥΛΟΥ ΚΑΙ ΕΛΑΣΤΙΚΩΝ ΟΧΗΜΑΤΩΝ : [ Production and properties of experimental bricks for interior walls from gypsum and recycled materials of wood and rubber ]
- 2017
-
Ingår i: ΠΡΑȀΤǿȀΑ : 18ου Πανελλήνιου Δασολογικού Συνεδρίου : “Η Ελληνική Δασοπονία μπροστά σε σημαντικές προκλήσεις: αειφορική διαχείριση δασών, δασικοί χάρτες, περιβαλλοντικές τεχνολογίες – δικτύωση και προστασία φυσικού περιβάλλοντος”. - : Hellenic Forestry Society. - 9789608947870 ; , s. 315-323
-
Konferensbidrag (refereegranskat)abstract
- Τhe manufacturing and testing of gypsum bonded solid bricks with wood chips from particleboard production residues and rubber and textile fibers from waste tires was investigated. The recovered rubber and wood materials were mixed in gypsum/water solutions for the fabrication of standard solid bricks with six holes by using appropriate molds. After drying, the compressive strength, the thermal conductivity, the air-flow resistance, the sound absorption coefficient and the emissions of volatile organic compounds (VOC) of the bricks were determined. The compressive strength of solid bricks was much greater than that required in interior walls. The bricks showed a better thermal insulation than both the extruded and pressed house bricks but lower than the insulating bricks. Emissions of volatile organic compounds of bricks were at acceptable levels according to regulations for construction products. The sound absorption coefficient of the solid bricks was 0,72 for the frequency of 1 kHz and decreased with increasing frequency. In addition, information on the raw materials and production cost are given.
|
|
