User:Yu.sea/sandbox

Article evaluation

Wikipedia article: Green building

• Is everything in the article relevant to the article topic? Is there anything that distracted you?

Majority of the article was related to the main topic of the article and contained a vast amount of knowledge regarding green buildings. The article gave ample information to the different subtopics that were mentioned, for example siting and structure efficiency, waste reduction, water treatment, etc. Not much distracted me in the article, however, I found it peculiar how long the paragraph for cost and pay off was.

• Is the article neutral? Are there any claims, or frames, that appear heavily biased toward a particular position?

The article could be considered a little biased because there was not much criticism towards green buildings and the article did not highlight the various challenges of constructing a green building.

• Are there viewpoints that are overrepresented, or underrepresented?

Not much representation towards challenges that green buildings face.

• Check a few citations. Do the links work? Does the source support the claims in the article?

Some links work, like citation 25 and 47. However, some citations do not work, like 45 and 46.

• Is each fact referenced with an appropriate, reliable reference? Where does the information come from? Are these neutral sources? If biased, is that bias noted?

Majority of the references come from scientific journals or government articles which are mostly neutral and reliable sources.

• Is any information out of date? Is anything missing that could be added?

Most of the information was up to date, however there are a few things that could possibly be out of date. I am not too sure that the fact about California's construction waste is correct as it dates back to 2003.

• Check out the Talk page of the article. What kinds of conversations, if any, are going on behind the scenes about how to represent this topic?

Majority of the conversations were regarding changes in wikipedia page but also discussions on various points made in the wikipedia page.

• How is the article rated? Is it a part of any WikiProjects?

The article I looked at was rated B for WikiProject environment and not rated for WikiProject Architecture.

Wikipedia Article Ideas

Initially I wanted to write about "sustainable building methodology" or "building resiliency methods". The wikipedia page Urban resilience exists but needs a lot of updating so I could expand this wikipedia page. There is also already a Green building wikipedia page, there are various parts of this article I can expand from, for example the wikipedia page very briefly mentions "Structural Design Efficiency" and has a section on "Material Efficiency" so I could expand on each of those sections. I could also add a section on "Sustainable Structural Engineering" or even make a separate wikipedia page with this topic.

Wikipedia Article - Final Choice

In the end I chose to edit the article "Cross Laminated timber". At the time of writing this the article was rated a start class with low importance. Just from reading the article some of the information can be reorganised and a much better article structure can be implemented.

Wikipedia Article Draft

Introduction // Keep from before and added a few sentences.

Cross-laminated timber (CLT) is a wood panel product made from solid-sawn lumber. Each layer of boards is orientated perpendicular to the previous layers and glued on the wide faces of each board. Typically, CLT is manufactured with an odd number of layers to maintain symmetry but configurations of even number layers are also possible. Since regular timber is an anisotropic material, meaning that the structural properties change depending on the direction at which the force is applied, gluing timber layers at perpendicular angles achieves structural rigidity in two directions. It is similar to plywood but with distinctly thicker laminations.

CLT is the opposite to glued laminated timber (GLT), a product with all laminations orientated in the same way.[1]

In 2016, plans were proposed for a 40-storey CLT building in Stockholm and a 100-storey tower in London.[2] 

Origin

CLT was first developed and used in Germany and Austria in the early 1990s but it was only after the mid 1990s more extensive research was completed. By the 2000s CLT saw much wider usage in Europe, being used in various building systems such as single-family and multi-story housing. The main reasons behind the rise of CLT were because of its sustainability and lack detrimental effects to the environment, but also improved marketing and availability.

Building Code Requirements

In 2015 CLT was incorporated into the national design specification for wood construction. This specification was used as a reference for the 2015 international building code, in turn allowing CLT to be recognised as a code compliant construction material. These code changes permitted CLT to be used in the construction of exterior walls, floors, partition walls and roofs. Also included in IBC 2015 were char rates for fire protection, connection provisions and fastener requirements specific to CLT. To meet structural performance requirements, the code mandated that structural CLT products met the requirements specified by ANSI/APA PRG 320.

Manufacturing

The manufacturing of CLT can be split up into nine steps, primary lumber selection, lumber grouping, lumber planing, lumber cutting, adhesive application, panel lay-up, assembly pressing, quality control and finally marketing and shipping.

The primary lumber selection consists of two to three parts, moisture content check, visual grading and sometimes depending on the application structural testing. Depending on the results of this selection, the timber fit for CLT will be used to create either construction grade CLT or appearance grade CLT. Timber that cannot fit into either category may be used for different products such as plywood or glued laminated timber.

The grouping step ensures the timber of various categories are grouped together. For construction grade CLT, the timber that has better structural properties will be used in the interior layers of the CLT panel while the two outermost layers will be of higher aesthetic qualities. For aesthetic grade CLT, all layers will be of higher visual qualities.

The planning step improves the surfaces of the timber. The purpose of this is to improve the performance of the adhesive between layers. Approximately 2.5mm is trimmed off the top and bottom faces and 3.8mm is trimmed off the sides to ensure a flat surface.There are some cases in which only the top and bottom faces are treated, this is typically the case if the sides do not have to be adhered to another substance. It is possible that this step may change the overall moisture content of the timber, however this is rarely happens.

The timber is then cut to a certain length depending on the application and clients needs.

The adhesive is then applied to the timber, typically through a machine. It is important to note that application of the adhesive must be airtight to ensure there are no holes or air gaps in the glue and that the adhesive is applied at a constant rate.

A panel lay-up is performed to stick the individual timber layers together. According to section 8.3.1 of the performance standard ANSI/AP PRG 320, at least 80% of surface area between layers must be bound together.

Assembly pressing fully completes the adhering process. There are two main types of pressing methods, vacuum pressing and hydraulic pressing. In vacuum pressing more than one CLT panel can be pressed at one time making the process more time and energy efficient. Another advantage to vacuum pressing is that it can apply pressure to curved shaped CLT panels because of the way the pressure is distributed around the whole structure. As for hydraulic pressing, advantages include higher pressures can be achieved and also the pressures placed on each edge can be specified.

Quality control is then performed on the CLT panels. Typically a sanding machine is used to create a better surface. The CLT panels are also cut to suit their specific design. Often, if the panels need to be conjoined to form longer structures finger joints are used.

Uses

In September 2016 the world's first timber mega-tube structure was built at the Chelsea College of Arts in London, using hardwood CLT panels. The 115 feet (35 m) long "Smile" was designed by architect Alison Brooks and engineered by Arup, in collaboration with the American Hardwood Export Council, for the London Design Festival.[3]

With its 3,852 cubic metres of CLT, Dalston Lane at Dalston Square is the largest CLT project globally. The project finishes in 2017. Ramboll carried out full structural engineering and the design of the 33m CLT structure. B&K Structures, a specialist hybrid frame contractor, was the structural frame and CLT provider. [4][5]

In the United States, Framework in Portland, Oregon will utilize CLT for its 12-storey structure to become the tallest timber building in America. This structure will utilize CLT panels in the flooring system and will also have the first CLT post-tensioned rocking wall core as the lateral seismic system. The construction for this project is expected to start early 2018.

In Australia, a nine-storey all-timber office building is due to be completed in Brisbane in late 2018.[7] Because of CLT’s ability to be prefabricated construction was finished six weeks earlier than predicted. Due to CLT being lighter than traditional construction materials, 20% more usable space was generated.

The current tallest CLT structure is UBC’s Brock Commons Residence hall. The building is approximately 53 meters tall with 18 storeys. 17 storeys use CLT as the floor panels and glued laminated timber as the columns. It is estimated that the carbon dioxide emissions were reduced by 2432 tonnes when compared to using traditional materials.