Flexural, in-plane shear and nail shear properties of falcataria-rubberwood laminated veneer board for flooring

Holzforschung ◽  
2008 ◽  
Vol 62 (6) ◽  
Author(s):  
Kweonhwan Hwang ◽  
EeDing Wong ◽  
Kohei Komatsu

Abstract A research project has been conducted to develop structural laminated veneer lumber products from tropical wood, and to evaluate their feasibility for the structural components of wooden houses. As part of this project, we investigated the flexural, in-plane shear, and nail shear properties of laminated veneer board (LVB) manufactured from a combination of falcataria (Paraserianthes falcataria) and rubberwood (Hevea brasiliensis) for flooring applications. In addition, 11-ply larch (Larix leptolepis) and 7-ply radiata pine (Pinus radiata) plywood were investigated as controls. Larch plywood, bonded with phenol-based adhesive, showed the best strength properties in bending and shear tests, whereas the 12-ply (28 mm thick) resorcinol-based resin-bonded LVB had the highest ductility in nail shear. The LVB also had better bending and shear properties than radiata pine plywood. In conclusion, falcataria-rubberwood LVB demonstrated good potential to substitute larch plywood and radiata pine plywood in flooring applications.

2020 ◽  
Vol 5 (1) ◽  
pp. 711-725
Author(s):  
Sutrisno ◽  
Eka Mulya Alamsyah ◽  
Ginanjar Gumilar ◽  
Takashi Tanaka ◽  
Masaaki Yamada

AbstractThe properties of the laminated veneer lumber (LVL) composed of the boiled veneer of Rubberwood (Hevea brasiliensis) using polyvinyl acetate (PVAc) adhesives in various cold-pressing time and various conditioned time with loaded and unloaded were studied. Five-ply LVL was produced by boiling veneer at 100°C for 90 min as pretreatment and cold-pressing time at 12 kgf cm−2 for 1.5, 6, 18, and 24 h then conditioned at 20°C and 65% relative humidity (RH) with loaded (12 kgf cm−2) and unloaded for 7 days as physical treatment. Especially for the delamination test, the specimens were immersed at 70 ± 3°C for 2 h and dried in the oven at 60 ± 3°C for 24 h; then, the specimens were solidified at room temperature (20°C and 65% RH) with loaded (12 kgf cm−2) and unloaded for 7, 10, 12, and 14 days. To determine the performance of LVL, the density, moisture content (MC), delamination, modulus of elasticity (MOE), modulus of rupture (MOR), horizontal shear strength, and formaldehyde emission tests were conducted according to the Japanese Agricultural Standard (JAS 2008) for structural LVL. The MOE and MOR values were significantly influenced by the physical treatment, however, neither to horizontal shear strength nor to formaldehyde emission. The best performance of LVL has resulted from unloaded LVL with cold-pressed time for 18 h; the MOE and MOR values were 9,345.05 ± 141.61 N mm−2 and 80.67 ± 1.77 N mm−2, respectively. The best value of the horizontal shear strength was obtained from the LVL with 18 h cold-pressing time and conditioned with loaded (13.10 ± 1.47 N mm−2) and unloaded (12.23 ± 1.36 N mm−2). The percentage of delamination values decreased with an increase in the cold-pressing time and conditioning time. The lowest value of delamination (19.06%) was obtained from the LVL with 24 h cold-pressing time and conditioned with loaded for 14 days. Except the delamination test, all other properties fulfilled the JAS.


2017 ◽  
Vol 61 ◽  
pp. 396-403 ◽  
Author(s):  
Aswani Kumar Bandaru ◽  
Vijay Kumar Mittal ◽  
Suhail Ahmad ◽  
Naresh Bhatnagar

2018 ◽  
Vol 53 (21) ◽  
pp. 3033-3045 ◽  
Author(s):  
MA Abd El-baky ◽  
MA Attia

The main objective of the present paper is to study the water absorption of jute–glass–carbon-reinforced epoxy composites and its subsequent effect on the in-plane shear performance of these composites. The effects of the reinforcement hybridization, stacking sequence and relative fabric amounts on the shear behavior of dry and wet conditioned composite specimens are reported and discussed. Composites have been fabricated in inter-ply configuration using the hand lay-up process. The prepared specimens have been subjected to distilled water and sea water immersion at room temperature for 60 days. Results indicated that water uptake of jute-reinforced composite and its hybrids with glass and/or carbon follows Fickian-like behavior. Water uptake induces a significant decrease in the in-plane shear strength. Hybridizing jute fabric with glass and/or carbon fabrics improves the in-plane shear properties of both dry and wet specimens. The stacking sequence and relative fabric amounts have a noticeable effect on the studied shear properties. Also, the hybrid composite with jute as facings and glass as core, JGJ, offers the most balanced set of properties on a cost-effective basis compared to the other studied hybrids.


Author(s):  
F. Longo ◽  
A. Cascardi ◽  
P. Lassandro ◽  
M. A. Aiello

AbstractAll over the world, a large part of existing buildings is not adequate to satisfy the safety requirement and the thermal comfort criteria. For this reason, the interest in structural and energy retrofitting systems has steadily grown in the last decades. In this scenario, an innovative thermal resistant geopolymer mortar has been developed and used for Inorganic Matrix Composite (IMC) systems aimed to a combined seismic and energy new retrofitting technique. The geopolymer-based IMC is able to ensure competitive mechanical properties with respect to the traditional lime-based IMCs and, at the same time, a significant reduction in thermal conductivity. In this paper, an experimental program is reported considering small-scaled masonry panels with double-side IMC-retrofitting and determining both the in-plane shear strength and the thermal resistance. The experimental shear tests are aimed to compare the mechanical performance of the geopolymer innovative systems with those of the traditional lime-based ones. Moreover, the thermal resistance gain of the innovative solutions was measured and compared with traditional systems. The results evidenced the effectiveness of the proposed technique that significantly improved the performances of masonry walls from both the thermal and the mechanical point of view.


1994 ◽  
Vol 3 (2) ◽  
pp. 096369359400300 ◽  
Author(s):  
Michael R. Wisnom ◽  
M. I. Jones

Short beam shear tests have been carried out on square cross-section specimens cut from a 32 ply plate. By rotating the beams through 90° both interlaminar and in-plane strength can be measured with identical specimens. The in-plane shear strength was found to be at least 10% higher than the interlaminar strength.


2016 ◽  
Vol 55 ◽  
pp. 278-286 ◽  
Author(s):  
F. Taheri-Behrooz ◽  
M. Esmkhani ◽  
A. Yaghoobi-Chatroodi ◽  
S.M. Ghoreishi

2015 ◽  
Vol 77 (8) ◽  
Author(s):  
Shukur Abu Hassan ◽  
Yob Saed Ismail ◽  
Abdul Rahman Mohd. Sam ◽  
Umar Abdul Hanan ◽  
Mat Uzir Wahit

As a consequence of tropical climate featuring abundant rain and sunshine throughout the year, adhesive bonded joints undergo substantial exposure to moisture and elevated temperatures. It is known that the degradation of adhesive materials such as structural epoxy due to weathering could affect the overall bond performance of structural integrity of reinforced concrete such as carbon fibre reinforced polymer composites (CFRP) plate system. The objective of the study is to investigate the in-plane shear properties of structural epoxy material exposed to tropical environmental conditions using Arcan Test Method. The epoxy adhesive was casted in a closed metal mould to produce butterfly shaped specimens. The specimens were exposed to four conditions; laboratory, outdoor, plain water, and salt water. The specimens were tested for shear properties and failed in brittle form. Microstructure analysis was performed to study the fracture surface of the test specimens. The study showed that the tropical exposure conditions influenced the shear strength of the epoxy material, especially for those exposed to plain and salt water conditions, which were 32% lower than the control specimen for specimens exposed to plain water followed by salt water (26.6%), laboratory (25.4%) and finally outdoor (18.4%).


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