Geopolymer as a multifunctional mineral binder to produce laminated veneer lumber: effect of various aluminosilicate powder types on panels and geopolymer binder features

Author(s):  
Farzaneh Allahverdipoorazar ◽  
Ali Shalbafan ◽  
Dirk Berthold
2020 ◽  
Vol 10 (2) ◽  
pp. 593 ◽  
Author(s):  
Ali Shalbafan ◽  
Heiko Thoemen

Environmentally friendly and formaldehyde-free laminated veneer lumber (LVL) was manufactured using geopolymer constituents as binder. The main aim of the study was to improve the bonding quality between the geopolymer binder and the wood constituents. To this end, the effect of various additives (phenol flakes, conventional silica fume, and grafted silica fume with 3-aminopropyltriethoxysilane (APTES)) in the geopolymer binder features were explored via gel time and viscosity measurements, differential scanning calorimetry (DSC), and Fourier transom infrared spectroscopy. The mechanical properties (shear, bending, and compression) of LVL panels were also determined. Results showed that adding both types of silica fume had a positive impact on the geopolymer binder features. The formation of an alkaline aluminosilicate network was proven by observing the characteristics peaks of geopolymer binder at about 683 and 970 cm−1. A peak temperature of about 98 °C was determined for the geopolymer binder curing via DSC analysis. The mechanical properties were the highest for LVL panels made of geopolymer binder with grafted silica fume. It is feasible that the APTES used as grafting agent created a better bonding mechanism with superficial wood cells. In summary, the produced LVL panel showed good properties, but it still needs to be further improved to reach the required levels for use in interior and humid application.


Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3440
Author(s):  
Mohd Na’im Abdullah ◽  
Mazli Mustapha ◽  
Nabihah Sallih ◽  
Azlan Ahmad ◽  
Faizal Mustapha ◽  
...  

The utilisation of rice husk ash (RHA) as an aluminosilicate source in fire-resistant coating could reduce environmental pollution and can turn agricultural waste into industrial wealth. The overall objective of this research is to develop a rice-husk-ash-based geopolymer binder (GB) fire-retardant additive (FR) for alkyd paint. Response surface methodology (RSM) was used to design the experiments work, on the ratio of RHA-based GB to alkyd paint. The microstructure behaviour and material characterisation of the coating samples were studied through SEM analysis. The optimal RHA-based GB FR additive was formulated at 50% wt. FR and 82.628% wt. paint. This formulation showed the result of 270 s to reach 200 °C and 276 °C temperature at equilibrium for thermal properties. Furthermore, it was observed that the increased contents of RHA showed an increment in terms of the total and open porosities and rough surfaces, in which the number of pores on the coating surface plays an important role in the formation of the intumescent char layer. By developing the optimum RHA-based GB to paint formulation, the coating may potentially improve building fire safety through passive fire protection.


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.


Author(s):  
Anagi M. Balachandra ◽  
Nastaran Abdol ◽  
A.G.N.D. Darsanasiri ◽  
Kaize Zhu ◽  
Parviz Soroushian ◽  
...  

Author(s):  
DB Heyner ◽  
G Piazza ◽  
E Beeh ◽  
G Seidel ◽  
HE Friedrich ◽  
...  

A promising approach for the development of sustainable and resource-saving alternatives to conventional material solutions in vehicle structures is the use of renewable raw materials. One group of materials that has particular potential for this application is wood. The specific material properties of wood in the longitudinal fiber direction are comparable to typical construction materials such as steel or aluminum. Due to its comparatively low density, there is a very high lightweight construction potential especially for bending load cases. Structural components of the vehicle body are exposed to very high mechanical loads in the case of crash impact. Depending on the component under consideration, energy has to be absorbed and the structural integrity of the body has to be ensured in order to protect the occupants. The use of natural materials such as wood poses particular challenges for such applications. The material characteristics of wood are dispersed, and depend on environmental factors such as humidity. The aim of the following considerations was to develop a material system to ensure the functional reliability of the component. The test boundary conditions for validation also play a key role in this context. The potential of wood–steel hybrid design based on laminated veneer lumber and steel was investigated for use in a component subjected to crash loads such as the door impact beam. The chosen solution involves a separation of functions. A laminated veneer lumber-based beam was hybridized with a steel strip on the tension side. The steel strip was designed to compensate the comparatively low elongation at fracture of the wood and to ensure the integrity of the beam. The wooden component was designed for high energy absorption due to delamination and controlled failure during the impact, while maintaining the surface moment of inertia, i.e. the bending stiffness of the entire component. This approach was chosen to ensure the functional safety of the component, avoid sudden component failure and utilize the high potential of both materials. The tests carried out provided initial functional proof of the chosen solution. The hybridization achieved significantly higher deformations without sudden failure of the beam. In addition, bending capabilities were increased significantly compared to a beam without hybridization. In comparison with a state-of-the-art steel beam, the hybrid beam was not able to achieve the maximum deformation and the target weight of the hybrid beam. Further optimization of the hybrid beam is therefore necessary.


2012 ◽  
Vol 37 (1) ◽  
pp. 58-74 ◽  
Author(s):  
Kevin Tsai ◽  
David Carradine ◽  
Peter Moss ◽  
Andrew Buchanan

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