Wood Properties and Bonding Shear Strength of Hardwood Glulam After Fire Exposure

InCIEC 2015 ◽  
2016 ◽  
pp. 747-757
Author(s):  
Abdul Wahab Mohd Jamil ◽  
Jabar Khairul Azmi ◽  
Seok Sean How
Keyword(s):  
Shear Strength ◽  
Wood Properties ◽  
Fire Exposure ◽  
Bonding Shear Strength

Finite Element Analysis of Shear Strength of Reinforced Concrete Beams after Fire

2013 ◽  
Vol 671-674 ◽  
pp. 474-478 ◽  
Author(s):  
Kai Xiang ◽  
Guo Hui Wang ◽  
Bi Zhao
Keyword(s):  
Finite Element ◽  
Shear Strength ◽  
Reinforced Concrete ◽  
Exposure Time ◽  
Concrete Strength ◽  
Reinforced Concrete Beams ◽  
Rc Beams ◽  
Fire Exposure ◽  
Shear Span ◽  
Strength And Stiffness

Shear strength and stiffness of fire-damaged reinforced concrete (RC) beams were researched. The nonlinear finite element method (FEM) was developed to simulate shear strength of fire-damaged RC beams. Considering mechanical properties deterioration of concrete and steel reinforcing bar, the parameters of fire-damaged RC beams, including fire exposure time, shear span to depth ratios, concrete strength, diameters of stirrups and spacing of stirrups, were analyzed. Based on numerical analysis, the change of shear strength and stiffness of fire-damaged RC beams were identified. The results showed that shear strength and stiffness of fire-damaged RC beams changed under different parameters. With increase of fire exposure time or increase of shear span to depth ratio or decrease of concrete strength, shear strength and stiffness of fire-damaged RC beams descended obviously. With decrease of diameters of stirrups or increase of spacing of stirrups, shear strength of fire-damaged RC beams descended gradually, but stiffness of fire-damaged RC beams had little change.

scholarly journals Effect of Using Urea Formaldehyde Modified with Extracts in Plywood on Formaldehyde Emission

2021 ◽  
Vol 72 (3) ◽  
pp. 237-244
Author(s):  
Ugur Bilgin ◽  
Gursel Colakoglu
Keyword(s):  
Lung Cancer ◽  
Shear Strength ◽  
Urea Formaldehyde ◽  
Formaldehyde Emission ◽  
Corylus Avellana ◽  
Bark Extract ◽  
Advantages And Disadvantages ◽  
Ulmus Glabra ◽  
Forestry Industry ◽  
Bonding Shear Strength

Formaldehyde-based adhesives are used in the forestry industry. This is because formaldehyde is inexpensive, easy to use and resistant to moisture; it also has particular mechanical effects. Formaldehyde has both advantages and disadvantages. It is known that various diseases such as lung cancer occur in humans as a result of the release of formaldehyde into the air during and after board production. In this study, a urea formaldehyde glue mixture was prepared by using four different fillers (extract of maritime pine (Pinus pinaster) and elm (Ulmus glabra) bark, extract of hazelnut (Corylus avellana) husk and acorn tannins) at two different ratios. The bonding shear strength of pine (Pinus sylvestris) and spruce (Picea orientalis) plywood produced with urea formaldehyde adhesive was tested according to EN 314-1 standard. All plywood, except the plywood with acorn tannin, met the requirements of the standard. A formaldehyde emission test of the plywood was carried out in accordance with EN 713-3 standard. With this approach, it is possible to quickly determine formaldehyde emissions. Experimental results were obtained for subsequent measurements, including chamber tests. It was observed that the elm bark extract reduced the formaldehyde emission of pine plywood by 40 %, while other fillers reduced it by 3-37 %.

scholarly journals Engineered Bamboo’s Further Application: An Empirical Study in China

2018 ◽  
Vol 206 ◽  
pp. 02005 ◽  
Author(s):  
WQ Xing ◽  
JL Hao ◽  
I Galobardes ◽  
SB Wei ◽  
ZT Chen ◽  
...  
Keyword(s):  
Shear Strength ◽  
Construction Industry ◽  
Construction Materials ◽  
Adverse Impact ◽  
Lightweight Construction ◽  
Preliminary Testing ◽  
Seismic Properties ◽  
Laminated Bamboo ◽  
Bonding Shear Strength ◽  
Clamping Pressure

The trend of sustainable development has been followed more globally nowadays. There is an urgent need for ecological friendly construction materials in China since the use of concrete produces pollution and leads to inefficient use of energy. Bamboo can effectively address the sustainability trends due to: lightweight construction, little adverse impact on the environment, and anti-seismic properties. However, bamboo products utilization has been very limited. Therefore, the purpose of this study was to investigate the feasibility to further utilize bamboo products in the construction industry in China. A review of engineered bamboo products utilization in China, and oversees was conducted. Based on this, a survey focusing on the current situation and suitability of bamboo products was carried out to study their feasibility, and preliminary testing on bonding shear strength for different configurations are presented. The results are promising, in particular the relatively low clamping pressure of 0.6 MPa seems to be sufficient for bonding, and it is clear that engineered bamboo products have a great potential in China. However, further more comprehensive studies on the performance of the laminated bamboo are needed.

Adhesive bonding of CFRP: a comparison of different surface pre-treatment strategies and their effect on the bonding shear strength

2017 ◽  
Vol 31 (23) ◽  
pp. 2581-2591 ◽  
Author(s):  
Markus Schweizer ◽  
Dieter Meinhard ◽  
Simon Ruck ◽  
Harald Riegel ◽  
Volker Knoblauch
Keyword(s):  
Shear Strength ◽  
Adhesive Bonding ◽  
Treatment Strategies ◽  
Pre Treatment ◽  
Bonding Shear Strength

Dependence of shear strength on wood properties in cultivatedLarix sibirica

2011 ◽  
Vol 6 (4) ◽  
pp. 177-184 ◽  
Author(s):  
Katri Luostarinen ◽  
Henrik Heräjärvi
Keyword(s):  
Shear Strength ◽  
Wood Properties

Structural Performance of Fire-Retardant Treated Plywood: Effect of Elevated Temperature

Holzforschung ◽  
1999 ◽  
Vol 53 (5) ◽  
pp. 547-552 ◽  
Author(s):  
Song-Yung Wang ◽  
Yu-Chen Rao
Keyword(s):  
Shear Strength ◽  
Elevated Temperature ◽  
Thermal Degradation ◽  
Bending Strength ◽  
Fire Retardant ◽  
Radiata Pine ◽  
Accelerated Degradation ◽  
Treatment Conditions ◽  
Bonding Shear Strength ◽  
Residual Weight

Summary This paper was designed to investigate the change of bending strength, bonding shear strength and surface fire-retardant (FR) performance of FR treated plywood after accelerated degradation treatment at elevated temperature (77 °C) and medium humidity (50%RH) condition. Furthermore, thermogravimetry analysis (TGA) and differential scanning curves (DSC) analysis were also conducted to explore their thermal degradation. PF-bonded Red meranti (Shorea spp.) and radiata pine (Pinus radiata) plywood, FR chemicals of AF21 and Lee-An 302 were used. Results indicated that the bending strength and bonding shear strength of non-FR treated and FR treated plywood decreased linearly with the increase of treatment durations. After 80 days of accelerated degradation treatment, the reduction ratio ( %) of bending strength ranged from 6.5% to 33.4% and varied with treatment conditions, whereas 12.8% to 42.3% reduction ratios were observed in bonding shear strength. After subjected to accelerated degradation treatment FR treated plywood could meet the requirement of the third grade FR performance as specified by CNS 6532 standard except those treated with Lee-An 302 FR for 20 days and 40 days. Furthermore, based on TGA, the weight loss of FR treated plywood was found to be less than that of non-FR treated plywoods. After thermal degradation under 100°C, the residual weight of FR treated plywood was higher than that of non-FR treated plywoods.

scholarly journals Effects of moisture content on lap-shear, bending, and tensile strength of lap-jointed and finger-jointed southern pine using phenol resorcinol formaldehyde and melamine urea formaldehyde

BioResources ◽  
2020 ◽  
Vol 15 (2) ◽  
pp. 3534-3544 ◽  
Author(s):  
Jian Liu ◽  
Kong Yue ◽  
Feng Wang ◽  
Jinhao Wu ◽  
Zhongqiu Tang ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Shear Strength ◽  
Bending Strength ◽  
Urea Formaldehyde ◽  
Southern Pine ◽  
Resorcinol Formaldehyde ◽  
Bonding Performance ◽  
Lap Shear ◽  
Bonding Shear Strength ◽  
Shear Bending

The bonding performance of the phenol-resorcinol-formaldehyde adhesive (PRF) and melamine-urea-formaldehyde adhesive (MUF) with southern pine as substrates at various moisture contents (MC) was evaluated. The results showed that bonding shear strength with MUF and PRF was negatively related to wood MC, and bonding shear strength with MUF was higher than that of the PRF. The bending and tensile strengths of finger-jointed lumber decreased with wood MC. The bending strength of finger-jointed lumber was affected more by wood than adhesive. However, both wood and adhesive exhibited the same important contribution to the tensile strength.

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