wood beams
Recently Published Documents


TOTAL DOCUMENTS

125
(FIVE YEARS 18)

H-INDEX

15
(FIVE YEARS 1)

2021 ◽  
Vol 26 (6) ◽  
pp. 527-534
Author(s):  
Jianquan LI ◽  
Yue YUAN ◽  
Shuzheng LUO

Wooden furniture production consumes a lot of forest resource and other resources, so it is important to estimate its environmental effect. In this research, we collected data in a sofa factory of China and appraised its environment impacts by the ecological footprint (EF) methodology. The results showed that the total EF of the sofa factory was 2 316.25 gha/year (gha: global hectare). The average EF of a sofa was 0.18 gha/year. For the total EF of the sofa factory, main contribution came from wooden materials (55%), followed by non-wooden materials (41.26%), and these two categories contributed above 96% of the total EF. Human labor accounted for 2.21% of the total footprint. The built land and water contributed a little to the total EF. For the total EF of the wooden materials, main contribution came from wood beams (57.6%), followed by plywood (41.08%); and for the total EF of the non-wooden materials, main contribution came from sponge (95.37%). In the end, we concluded that the incorporate of recycled wooden material and reused sponge in the sofa production could be viewed as an important strategy to achieve more sustainable manufacturing.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Tong Wang ◽  
Jing Di ◽  
Hongliang Zuo

PurposeIn view of the defects of glued wood beams, a new composite member – reconstituted bamboo board reinforced glued wood beams is proposed to improve the bearing capacity of glued wood beams.Design/methodology/approachThe bending test studied the ordinary glulam beams and the reinforced glulam beams with different layer numbers and different layer thicknesses by comparing with six kinds of glulam beams strengthened with bamboo scrimber and one kind of ordinary glulam beams and used the method of third-point stepwise loading on the glulam beams strengthened with bamboo scrimber.FindingsThe bamboo scrimber improved the bending behavior of the ordinary glulam beams. The 10 mm bamboo scrimber layer can meet the requirements of the maximum ultimate bending capacity and minimize the defects. So 10 mm bamboo scrimber layer was the optimal thickness. During the loading process, the strain change of the normal section of the reconstituted bamboo board reinforced glued wood beam basically conforms to the plane section assumption.Originality/valueThe bending rigidities of the glulam beams strengthened with bamboo scrimber increased up to 28.25%, 8.53% and 76.67%, and the ultimate bending capacity increased from 83.44% to 99.34% with the increase of the bamboo scrimber plate layers (the replacement rate). The ultimate bending capacities and the bending rigidities of the glulam beams strengthened with bamboo scrimber increased to 52.32%∼60.18% and 90.07%∼99.34% with the changing of the bamboo scrimber thicknesses from 7.1 mm to 25 mm.


2021 ◽  
Vol 13 (10) ◽  
pp. 5356
Author(s):  
Valérie Nsouami ◽  
Nicaise Manfoumbi ◽  
Rostand Moutou Moutou Pitti ◽  
Emilio Bastidas-Arteaga

Timber is a renewable material that should be more used for sustainable construction. While the mechanical behavior and durability of some species have been widely studied in the past, few studies are available for the Ozigo (Dacryodes buettneri) specie. This paper deals with the spatial variability of Ozigo beams subjected to long-term loadings and different environmental conditions. These beams were previously subjected to long-term creep in three environments (air-conditioned, unsheltered, and sheltered) at Masuku in the south-east of Gabon. Various specimens were extracted from these beams to determine its moisture content and subjected to three-point bending tests to obtain the modulus of elasticity and failure stress at various points in the space. The results obtained showed that, after long-term loadings, environmental exposure combined with mechanical loading, play a key role in the mechanical properties of the timber beams. A reduction of strength was found for the specimens extracted from the unsheltered and sheltered outdoor exposures in comparison with those extracted from the air-conditioned exposure. Concerning the spatial variability, statistical tests confirm that there is significant spatial correlation. It was also found that the spatial variation of properties in the beam is not stationary because it was affected by loading and support conditions.


Author(s):  
A. K. Yusupov ◽  
H. M. Muselemov ◽  
T. O. Ustarhanov

Objective. The development of structures and calculation of metal-wood crane beams are associated with specific difficulties. The article discusses the methods of calculation and design of metal-wood crane beams. In this case, an algorithm is described that allows designing systems that are rational in terms of material consumption. Methods. As an example, a metal-wood beam with a span of 12 m is used, which is supported by overhead cranes with a load capacity of 30 tf. The operation of a metal-wood crane beam was compared with a glue laminate crane beam without reinforcement. The reinforcement elements are "discarded" and replaced with elasto-yielding supports to calculate a glue laminate beam reinforced with metal elements (or a metal-wood beam). The flexibility of these supports is taken into account using the elastic support ratio r, which is determined depending on the stiffness of the supports, and the force in the metal elements is derived from the nodes balance. Result. In both variants of loading metal-wood crane beams, it was shown that the greatest bending moment occurred when the bridge wheel was located above the elastic support. Conclusion. It is rational to use a metal-wood crane beam when operating bridge cranes with a lifting capacity of up to 30 tf; metal-wood crane beams are recommended to be designed with spans up to 12 m; the comparison of glue laminate crane beams with metal-wood beams showed that metal-wood beams were 40-55% more efficient.


2020 ◽  
Vol 20 (2) ◽  
pp. 89-97
Author(s):  
Tiago Hendrigo de Almeida ◽  
Fabiane Salles Ferro ◽  
Diego Henrique de Almeida ◽  
Francisco Antonio Rocco Lahr

Abstract Glulam are long engineered wood beams (or columns) composed by graded lumbers bounded together with the use of appropriate adhesives under pre-established pressure. The greater the industrialization the greater will be the production of wood waste a matter that deserves attention and development of technologies in terms of its waste management. This paper aimed to investigate the technical feasibility of Brazilian industrial glulam waste usage as raw material for particleboard production industries using a castor oil-based polyurethane adhesive. Particleboards were manufactured using glulam (produced with Eucalyptus urograndis) waste particles and castor oil-based polyurethane adhesive at 8, 10, 12 and 14% mass proportions and characterized based on NBR 14810-2:2006 procedures. Analysis of variance was performed for the comparison of mechanical and physical performances of the panels. The increase of adhesive content caused and increase of the MOR (Rupture Modulus), but the MOE (Elasticity Modulus) and the physical properties remained unaltered above 12% of adhesive content. The adhesive content greater than 8% provided panel performances that met the standardized specifications. Based on these findings, it was possible to conclude that the waste of glulam produced with Eucalyptus urograndis can be used as raw material for particleboard production.


Author(s):  
Reginald Murphy

Chapter 14 investigates the archaeology, technology, and restoration of the Betty’s Hope north windmill. Archaeological excavations and restoration work were conducted from 1988 to 1995. Today, 90 stone towers are all that remain of the windmills scattered across Antigua’s landscape. This project initiated archaeological research at Betty’s Hope as well as cultural heritage management of the site. As one of the largest and most lucrative estates on Antigua, Betty’s Hope could afford two windmills to crush the sugar cane by harnessing wind power and utilizing the horizontal three-roller system. The mid-nineteenth century witnessed the conversion to steam-powered at Betty’s Hope. Restoration efforts included replacing parts of the original stone floor, old hard wood beams, masonry, cap house, arms, and machinery.


Sign in / Sign up

Export Citation Format

Share Document