The influences of moisture content variation, number and width of gaps on the withdrawal resistance of self tapping screws inserted in cross laminated timber

Published Date
doi:10.1016/j.conbuildmat.2016.09.008

Author 

Catarina Silva ^a,,

Jorge M. Branco ^a,

Andreas Ringhofer ^b,

Paulo B. Lourenço ^a,

Gerhard Schickhofer ^b,

aISISE, Univ. of Minho, Dept. of Civil Engineering, Portugal

bInstitute of Timber Engineering and Wood Technology, Graz Univ. of Technology, Austria

Received 30 December 2015. Revised 30 August 2016. Accepted 2 September 2016. Available online 9 September 2016.

Highlights

• Withdrawal resistance   of self-tapping screws inserted in CLT is presented.
• •
  Effects of moisture content (MC) variation and existence of gaps were analyzed.
• •
  Increase of MC causes the reduction of   for almost all test configurations.
• •
  Relative humidity cycle results in high decreases of  .

Abstract 

A large experimental campaign comprised of 470 withdrawal tests was carried out, aiming to quantify the withdrawal resistance of self-tapping screws (STS) inserted in the side face of cross laminated timber (CLT) elements. In order to deeply understand the “CLT-STS” composite model, the experimental tests considered two main parameters: (i) simple and cyclic changes on moisture content (MC) and (ii) number and width of gaps. Regarding (i), three individual groups of test specimens were stabilized with 8%, 12% and 18% of moisture content and one group was submitted to a six month RH cycle (between 30% and 90% RH). Concerning (ii), different test configurations with 0 (REF), 1, 2 and 3 gaps, and widths equal to 0 mm (GAP0) or 4 mm (GAP4), were tested. The influences of MC and number of gaps were modeled by means of least square method. Moreover, a revision of a prediction model developed by Uibel and Blaß (2007) was proposed.

The main findings of the experimental campaign were: the decrease of withdrawal resistance for specimens tested with MC = 18% in most configurations; the unexpected increase of withdrawal resistance as the number of gaps with 0 mm increased; and, the surprising increase of withdrawal resistance for REF specimens submitted to the RH cycle.

Keywords

Cross laminated timber

Self-tapping screws

Moisture content variation

Withdrawal resistance

Axial loading

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Table 1.

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 Table 2

Table 2.

 Table 3

Table 3.

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Fig. 9.

• ⁎ 
  Corresponding author at: Campus de Azurém, 4810-058 Guimarães, Portugal.
  
  

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Informing the improvement of forest products durability using small angle neutron scattering

Published Date
Original Paper

First Online: 

15 April 2016

DOI: 10.1007/s10570-016-0933-y

Cite this article as: 

Plaza, N.Z., Pingali, S.V., Qian, S. et al. Cellulose (2016) 23: 1593. doi:10.1007/s10570-016-0933-y

Author

Nayomi Z. Plaza

Sai Venkatesh Pingali

Shuo Qian

William T. Heller

Joseph E. Jakes

Abstract

A better understanding of how wood nanostructure swells with moisture is needed to accelerate the development of forest products with enhanced moisture durability. Despite its suitability to study nanostructures, small angle neutron scattering (SANS) remains an underutilized tool in forest products research. Nanoscale moisture-induced structural changes in intact and partially cut wood cell walls were investigated using SANS and a custom-built relative humidity (RH) chamber. SANS from intact wood sections cut from each primary wood orientation showed that although wood scattered anisotropically across 1.3–600 nm length scales, measurement of elementary fibril spacing and low-q surface scattering were independent of orientation. Water sorption caused spacing between elementary fibrils to increase with RH, and this swelling accounted for over half the transverse swelling in S2 secondary wood cell walls. Elementary fibril spacing in longitudinally cut wood cells, which were designed to mimic cells near wood-adhesive bondlines, was greater than the spacing in intact cells above 90 % RH. This suggested that some cell wall hoop constraint from the S1 and S3 cell wall layers on the S2 layer was released by cutting the cells. Furthermore, increased spacing between elementary fibrils may also create diffusion channels that are hypothesized to be responsible for the onset of fungal decay in wood. Protocols were established to use SANS in future research to study adhesives and protection treatments to improve moisture durability in forest products.

References

1. Arnold O, Bilheux JC, Borreguero JM et al (2014) Mantid—data analysis and visualization package for neutron scattering and μSR experiments. Nucl Instrum Methods Phys Res Sect A Accel Spectrometers, Detect Assoc Equip 764:156–166. doi:10.1016/j.nima.2014.07.029CrossRefGoogle Scholar
2. Atalla RS, Crowley MF, Himmel ME, Atalla RH (2014) Irreversible transformations of native celluloses, upon exposure to elevated temperatures. Carbohydr Polym 100:2–8. doi:10.1016/j.carbpol.2013.06.007CrossRefGoogle Scholar
3. Bergman R, Puettmann M, Taylor A, Skog KE (2014) The carbon impacts of wood products. For Prod J 64:220–231. doi:10.13073/FPJ-D-14-00047Google Scholar
4. Berry SL, Roderick ML (2005) Plant-water relations and the fibre saturation point. New Phytol 168:25–37. doi:10.1111/j.1469-8137.2005.01528.xCrossRefGoogle Scholar
5. Bondeson D, Mathew A, Oksman K (2006) Optimization of the isolation of nanocrystals from microcrystalline cellulose by acid hydrolysis. Cellulose 13:171–180. doi:10.1007/s10570-006-9061-4CrossRefGoogle Scholar
6. Bouteje JB (1962) The relationship of structure to transverse anisotropy in wood with reference to shrinkage and elasticity. Holzforschung 16:33–46CrossRefGoogle Scholar
7. Cousins WJ (1978) Youngs modulus of hemicellulose as related to moisture-content. Wood Sci Technol 12:161–167CrossRefGoogle Scholar
8. Derome D, Griffa M, Koebel M, Carmeliet J (2011) Hysteretic swelling of wood at cellular scale probed by phase-contrast X-ray tomography. J Struct Biol 173:180–190. doi:10.1016/j.jsb.2010.08.011CrossRefGoogle Scholar
9. Engelund ET, Thygesen LG, Svensson S, Hill CA (2013) A critical discussion of the physics of wood-water interactions. Wood Sci Technol 47:141–161. doi:10.1007/s00226-012-0514-7CrossRefGoogle Scholar
10. Fahlén J, Salmén L (2002) On the lamellar structure of the tracheid cell wall. Plant Biol 4:339–345. doi:10.1055/s-2002-32341CrossRefGoogle Scholar
11. Fernandes AN, Thomas LH, Altaner CM et al (2011) Nanostructure of cellulose microfibrils in spruce wood. Proc Natl Acad Sci 108:E1195–E1203. doi:10.1073/pnas.1108942108CrossRefGoogle Scholar
12. Frihart C (2005) Adhesive bonding and performance testing of bonded wood products. J ASTM Int 2:12952. doi:10.1520/JAI12952CrossRefGoogle Scholar
13. Glatter O, Kratky O (1982) Small angle X-ray scattering. Academic Press, LondonGoogle Scholar
14. Hanley S, Revol J-F, Godbout L, Gray D (1997) Atomic force microscopy and transmission electron microscopy of cellulose from Micrasterias denticulata; evidence for a chiral helical microfibril twist. Cellulose 4:209–220. doi:10.1023/A:1018483722417CrossRefGoogle Scholar
15. Heller WT, Urban VS, Lynn GW et al (2014) The Bio-SANS instrument at the high flux isotope reactor of Oak Ridge National Laboratory. J Appl Crystallogr 47:1238–1246. doi:10.1107/S1600576714011285CrossRefGoogle Scholar
16. Hernández RE, Bizoň M (1994) Changes in shrinkage and tangential compression strength of sugar maple below and above the fiber saturation point. Wood Fiber Sci 26:360–369Google Scholar
17. Howard ET, Manwiller FG (1969) Anatomical characteristics of southern pine stemwood. Wood Sci 2:77–86Google Scholar
18. Ilavsky J, Jemian PR (2009) Irena: tool suite for modeling and analysis of small-angle scattering. J Appl Crystallogr 42:347–353. doi:10.1107/S0021889809002222CrossRefGoogle Scholar
19. Ishimaru Y, Iida I (2001) Transverse swelling behavior of hinoki (Chamaecyparis obtusa) revealed by the replica method. J Wood Sci 47:178–184. doi:10.1007/BF01171219CrossRefGoogle Scholar
20. Jakes JE, Plaza N, Stone DS et al (2013) Mechanism of transport through wood cell wall polymers. J For Prod Ind 2:10–13Google Scholar
21. Jakob HF, Tschegg SE, Fratzl P (1996) Hydration dependence of the wood-cell wall structure in Picea abies. A small-angle X-ray scattering study. Macromolecules 29:8435–8440. doi:10.1021/ma9605661CrossRefGoogle Scholar
22. Kelley SS, Rials TG, Glasser WG (1987) Relaxation behaviour of the amorphous components of wood. J Mater Sci 22:617–624. doi:10.1007/BF01160778CrossRefGoogle Scholar
23. Kennedy CJ, Šturcová A, Jarvis MC, Wess TJ (2007) Hydration effects on spacing of primary-wall cellulose microfibrils: a small angle X-ray scattering study. Cellulose 14:401–408. doi:10.1007/s10570-007-9129-9CrossRefGoogle Scholar
24. Kulasinski K, Keten S, Churakov SV et al (2014) Molecular mechanism of moisture-induced transition in amorphous cellulose. ACS Macro Lett 3:1037–1040. doi:10.1021/mz500528mCrossRefGoogle Scholar
25. Kulasinski K, Guyer R, Derome D, Carmeliet J (2015a) Water adsorption in wood microfibril-hemicellulose system: role of the crystalline-amorphous interface. Biomacromolecules 16:2972–2978. doi:10.1021/acs.biomac.5b00878CrossRefGoogle Scholar
26. Kulasinski K, Guyer R, Derome D, Carmeliet J (2015b) Poroelastic model for adsorption-induced deformation of biopolymers obtained from molecular simulations. Phys Rev E 92:022605. doi:10.1103/PhysRevE.92.022605CrossRefGoogle Scholar
27. Kulasinski K, Guyer R, Keten S et al (2015c) Impact of moisture adsorption on structure and physical properties of amorphous biopolymers. Macromolecules 48:2793–2800. doi:10.1021/acs.macromol.5b00248CrossRefGoogle Scholar
28. Lai C, Zhou Z, Zhang L et al (2014) Free-standing and mechanically flexible mats consisting of electrospun carbon nanofibers made from a natural product of alkali lignin as binder-free electrodes for high-performance supercapacitors. J Power Sources 247:134–141. doi:10.1016/j.jpowsour.2013.08.082CrossRefGoogle Scholar
29. Lehmann S (2013) Low carbon construction systems using prefabricated engineered solid wood panels for urban infill to significantly reduce greenhouse gas emissions. Sustain Cities Soc 6:57–67. doi:10.1016/j.scs.2012.08.004CrossRefGoogle Scholar
30. Lichtenegger H, Müller M, Paris O et al (1999) Imaging of the helical arrangement of cellulose fibrils in wood by synchrotron X-ray microdiffraction. J Appl Crystallogr 32:1127–1133CrossRefGoogle Scholar
31. Lippke B, Wilson J, Perez-Garcia J et al (2004) CORRIM: life-cycle environmental performance of renewable building materials. For Prod J 54:8–19Google Scholar
32. Moon RJ, Martini A, Nairn J et al (2011) Cellulose nanomaterials review: structure, properties and nanocomposites. Chem Soc Rev 40:3941–3994. doi:10.1039/c0cs00108bCrossRefGoogle Scholar
33. Murata K, Masuda M (2006) Microscopic observation of transverse swelling of latewood tracheid: effect of macroscopic/mesoscopic structure. J Wood Sci 52:283–289. doi:10.1007/s10086-005-0760-5CrossRefGoogle Scholar
34. Nanda S, Mohammad J, Reddy SN et al (2014) Pathways of lignocellulosic biomass conversion to renewable fuels. Biomass Convers Biorefinery 4:157–191. doi:10.1007/s13399-013-0097-zCrossRefGoogle Scholar
35. Newman RH, Hill SJ, Harris PJ (2013) Wide-angle X-ray scattering and solid-state nuclear magnetic resonance data combined to test models for cellulose microfibrils in mung bean cell walls. Plant Physiol 163:1558–1567. doi:10.1104/pp.113.228262CrossRefGoogle Scholar
36. Nishiyama Y, Langan P, O’Neill H et al (2014) Structural coarsening of aspen wood by hydrothermal pretreatment monitored by small- and wide-angle scattering of X-rays and neutrons on oriented specimens. Cellulose 21:1015–1024. doi:10.1007/s10570-013-0069-2CrossRefGoogle Scholar
37. Oliver CD, Nassar NT, Lippke BR, McCarter JB (2014) Carbon, fossil fuel, and biodiversity mitigation with wood and forests. J Sustain For 33:248–275. doi:10.1080/10549811.2013.839386CrossRefGoogle Scholar
38. Olsson AM, Salmén L (2004) The association of water to cellulose and hemicellulose in paper examined by FTIR spectroscopy. Carbohydr Res 339:813–818. doi:10.1016/j.carres.2004.01.005CrossRefGoogle Scholar
39. Paris O, Müller M (2003) Scanning X-ray microdiffraction of complex materials: diffraction geometry considerations. Nucl Instruments Methods Phys Res Sect B Beam Interact Mater Atoms 200:390–396. doi:10.1016/S0168-583X(02)01728-7CrossRefGoogle Scholar
40. Pingali SV, Urban VS, Heller WT et al (2010) SANS study of cellulose extracted from switchgrass. Acta Crystallogr Sect D Biol Crystallogr 66:1189–1193. doi:10.1107/S0907444910020408CrossRefGoogle Scholar
41. Pingali SV, O’Neill HM, Nishiyama Y et al (2014) Morphological changes in the cellulose and lignin components of biomass occur at different stages during steam pretreatment. Cellulose 21:873–878. doi:10.1007/s10570-013-0162-6CrossRefGoogle Scholar
42. Rafsanjani A, Stiefel M, Jefimovs K et al (2014) Hygroscopic swelling and shrinkage of latewood cell wall micropillars reveal ultrastructural anisotropy. J R Soc Interface 11:20140126. doi:10.1098/rsif.2014.0126CrossRefGoogle Scholar
43. Robertson AB, Lame FCF, Cole RJ (2012) A comparative cradle-to-gate life cycle assessment of mid-rise office building construction alternatives: laminated timber or reinforced concrete. Buildings 2:245–270CrossRefGoogle Scholar
44. Rowell RM, Pettersen R, Tshabalala MA (2005) Cell wall chemistry. In: Rowell RM (ed) Handbook of wood chemistry and wood composites, 2nd edn. CRC Press, Boca Raton, pp 33–72Google Scholar
45. Rowell RM, Ibach RE, McSweeny J, Nilsson T (2009) Understanding decay resistance, dimensional stability and strength changes in heat-treated and acetylated wood. Wood Mater Sci Eng 4:14–22. doi:10.1080/17480270903261339CrossRefGoogle Scholar
46. Salmén L, Fahlén J (2006) Reflections on the ultrastructure of softwood fibers. Cellul Chem Technol 40:181–185Google Scholar
47. Sheldon RA (2014) Green and sustainable manufacture of chemicals from biomass: state of the art. Green Chem 16:950–963. doi:10.1039/C3GC41935ECrossRefGoogle Scholar
48. Stamm AJ (1971) Review of nine methods for determining the fiber saturation point of wood and wood products. Wood Sci 4:114–128Google Scholar
49. Stevanic JS, Salmén L (2009) Orientation of the wood polymers in the cell wall of spruce wood fibres. Holzforschung 63:497–503. doi:10.1515/HF.2009.094CrossRefGoogle Scholar
50. Tarkow H, Turner HD (1958) The swelling pressure of wood. For Prod J 8:193–196Google Scholar
51. Terashima N, Kitano K, Kojima M et al (2009) Nanostructural assembly of cellulose, hemicellulose, and lignin in the middle layer of secondary wall of ginkgo tracheid. J Wood Sci 55:409–416. doi:10.1007/s10086-009-1049-xCrossRefGoogle Scholar
52. Thomas LH, Altaner CM, Jarvis MC (2013) Identifying multiple forms of lateral disorder in cellulose fibres. J Appl Crystallogr 46:972–979. doi:10.1107/S002188981301056XCrossRefGoogle Scholar
53. Thomas LH, Forsyth VT, Martel A et al (2014) Structure and spacing of cellulose microfibrils in woody cell walls of dicots. Cellulose 21:3887–3895. doi:10.1007/s10570-014-0431-zCrossRefGoogle Scholar
54. Wiedenhoeft AC (2013) Structure and function of wood. In: Rowell RM (ed) Handbook of wood chemistry and wood composites, 2nd edn. CRC Press, Boca Raton, pp 9–32Google Scholar
55. Zelinka SL, Glass SV (2010) Water vapor sorption isotherms for southern pine treated with several waterborne preservatives. J Test Eval 38:102696. doi:10.1520/JTE102696CrossRefGoogle Scholar
56. Zelinka SL, Gleber S-C, Vogt S et al (2015) The threshold for ion movement in wood cell walls below fiber saturation observed by micro X-ray fluorescence microscopy. Holzforschung 69:441–448. doi:10.1515/hf-2014-0138CrossRefGoogle Scholar
57. Zhao JK, Gao CY, Liu D (2010) The extended Q-range small-angle neutron scattering diffractometer at the SNS. J Appl Crystallogr 43:1068–1077. doi:10.1107/S002188981002217XCrossRefGoogle Scholar

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