MECHANICAL CHARACTERIZATION OF STRUCTURAL GLULAM WIDELY USED FIVE SPECIES IN COLOMBIA

Transcription

1 MECHANICAL CHARACTERIZATION OF STRUCTURAL GLULAM WIDELY USED FIVE SPECIES IN COLOMBIA CÉSAR POLANCO TAPIA UNIVERSIDAD DISTRITAL, Bogotá D.C, Colombia ROSVEN ARÉVALO FUENTES UNIVERSIDAD DEL TOLIMA, Ibagué, Colombia NATALY LÓPEZ YELA UNIVERSIDAD DISTRITAL, Bogotá D.C, Colombia 2013 INTERNATIONAL CONFERENCE ON WOOD ADHESIVES, 9-11 OCT, TORONTO, CANADA

2 INTRODUCTION Raw material, from plantation Than native stands. More logged species from plantation are: Acacia, (Acacia mangium Willd.), Gmelina (Gmelina arborea Roxb.), Eucaliptus (Eucalyptus tereticornis Sm.) and Pino caribe (Pinus caribaea Morelet), and Sajo (Campnosperma panamense Standl.) from Tropical Rain Forest.

3 Colombian Forest Map Plantations: ha Natural Forest: ha Round mill Total : m 3 /year Pulp mill: m 3 /year Boards: m 3 /year Plywood: m 3 /year Saw mill: m 3 /year

4 INTRODUCTION Higth transport prices, and intermediaries wages "value-added wood products" in situ, will reduce costs and increases employment. Glulam can be a key factor in the country's forestry development, whith the increasing demand in construction sector. A deep gap in knowledge on sustentable use of plantation grown and native species.

5 INTRODUCTION To use wood more efficiently end-products specific characteristics as gluing performance must be taken into account. Large glulam members can be manufactured from a variety of smaller trees harvested from second- and third-growth forests and plantations (APA, 2008) The increasing demand for green products we can see that Engineering Wood Products (EWPs) have a potential to increase their market.

6 OBJECTIVES Evaluate the effect of four different kinds of adhesives on mechanical behavior of glulam elaborated with five species more used and commercialized in Colombia Calculate the costs per cubic meter of glulam elaborated with four adhesives and five species more used and commercialized in Colombia

7 MATERIALS AND METHODS MATERIALS Commercial resins MUF 1242 (80-20%), PRF 1711 (80-20%), PUR 1968, EPI 1974 (83-17%), were obtained from a colombian filial of Akzo Nobel and used as received. All other chemicals were supplied from the same brand and used as received. Four different species from plantation: Acacia, Gmelina, Eucaliptus and Pino caribe and one from tropical rain forest, Sajo.

8 Gmelina and Eucalipto Acacia and Pino Sajo

9 MATERIALS AND METHODS Wood from plantation and studs from sajo were processed into flat boards of 1.25 cm (R) x 83.0 cm (L), and variable wide (h) according to original sizes. All material were air dry, at laboratory conditions, to a 13-17% EMC.

10 MATERIALS AND METHODS Just prior to bonding all flat sawn boards were two faces planed with a four knives machine at a 10 m/min speed. Adhesives were prepared according to the manufacturer s specifications. The bonding surfaces of two pieces were coated with commercial resin with an adhesive coverage of 350 g/m 2. The coated laminate were then sandwiched together and pressed with four hydraulic jacks under 0.55 MPa each one, for 24 hours.

11 López, 2012

12 MATERIALS AND METHODS Curing time, of laminated boards, was seven days at laboratory conditions (80% HR; 12.5 C). Specimens were manufactured to achieve the conditions imposed by the standards ASTM D (Correal & Ramírez 2010)

13 MATERIALS AND METHODS WOOD BENDING TESTS Specimens were evaluated according to ASTM D (ASTM 2009) with an LOS universal testing machine (Model UHP 20). Load was applied at 6 mm/min until failure. Values of work at the proportional limit (SPL), modulus of rupture (MOR), strain, modulus of elasticity (MOE) and failure modes of wood specimens were recorder. After each test, small sections were cut for moisture content measurements.

14 López, 2012

15 MATERIALS AND METHODS DESIGNING A BEAM TYPE Based on the needs for a typical home construction, and following the guidelines seismoresistant code for Colombia (NSR 2010) a beam, able to carry the applied loads, was designed per each treatment mm (L) x 80 mm (w) and high (h) was calculate according to the strength values of each treatment. Cost per m 3 was calculate on wood and adhesive needed for the beam type.

16 MATERIALS AND METHODS Data were analyzed using descriptive statistics. Mechanical properties were assesed with the average values of those samples than reported a coefficient of variation less than 15%. After validation of the normality of the data an experimental design was assambled using three factors. The first associated with testing (A), the second to adhesives (B) and the third to the species used (C). The program used was Microsoft Excel 2010

17 RESULTS AND DISCUSION

18 Result of Bending Test Db= 437 Kg/m3 Db= 397 Kg/m3 Db= 535 Kg/m3 Db= 493 Kg/m3 Db= 861 Kg/m3

19 ΣKg/cm2 Σ Kg/cm Σ SPL and MOR for Species Σ MOE for Species Resistance added Value by adhesives for each Specie

20 Σ MOR and SPL for adhesives MUF PRF PUR EPI Σ MOE for adhesives Resistance added Value by Species for each Adhesive MUF PRF PUR EPI

21 THICKNESS PER TREATMENT FOR THE BEAM TYPE AND COST PER CUBIC METER

22 DISCUSION ANALYSIS OF VARIANCE FOR MOE AND COST FOR CUBIC METER FOR ALL TREATMENTS Source of Variation DF SS MS Fc Ft P Value A (MOE and $/m3) B (Adhesives) C (Species) AXB vs AXBXC ** p<0.025 AXC vs AXBXC ,52*** p<0.005 BXC vs AXBXC N.S. AXBXC

23 CONCLUSIONS The results showed an optimum mechanical performance for all wood/adhesive combinations because it was demonstrated that it is possible the design of glulam beam able to carry the solicited loads recommended by the seism resistant Colombian code NSR-10. Statistic analysis showed significative differences among adhesives and species when they were analyzed separated.

24 CONCLUSIONS The higher and lower MOE values are primary associated to more dense and less dense species respectively and secondary to adhesive (EPI). The case study shows that the treatment of highest values of resistance mechanical are not necessary the more economic in manufacture since the cost of raw material which are import parameters to define the final cost. It is recommended to explorer the treatment Sajo +EPI in a real scale in the construction industry in Colombia.

25 ACKNOWLEGEMENT The authors wish to thank the technicians and wood science professors, from Universidad Distrital Francisco José de Caldas and Universidad del Tolima, for their financial and technical support. To all wooden and chemical factories which donated raw material for this research.

26 THANK YOU!!!!!! César Polanco Rosven Arévalo Nataly López