Constructing Environment Week 7 studio journal Jianpeng Deng, 657598 This week, the e-‐learning section mainly focuses on the new materials for construction. First of all, ETFE is one of the new materials which is the cushions are manufactured from multiple layers of ETFE, is a modified co-‐polymer; An example is the swimming cube in Beijing and its very outer structure is made of cushions with triple layers, that as a part of the cushions inflects, it comes apart and allows the light to come in. ETFE is originally developed for the space industry and it is unique because it does not degrade under ultraviolet light or atmospheric pollution. Cross Laminated Timber (CLT), which is another new material, is an industrially prefabricated timber panel of superior strength. CLT’s structural performance is comparable with pre-‐cast concrete and it uses a formaldehyde-‐free polyurethane structured adhesive, which helps to make CLT more environmentally friendly; moreover, lightweight is another advantage of this material. On the other hand, we are also introduced a process called refabrication, an example of which is bamboo flooring and cork insulation; the similarity between them is that the manufacturing process is long and time-‐consuming, but the materials are very of use in construction. Besides, the topic for this week is roof systems; we are introduced in detail about the key concepts of roofs, for instance, there are three types of flat roofs, frame, concrete and hybrid, it is very important to know that all of them require water proof, otherwise if there is too much rainwater on the roof, it will turn out water leakage. Apart from the big pictures of roof systems, we are also introduced the small details of them, such as, gutter, flashing and purlin. For example, gutter is commonly made of metal positioned below along the eave of roofs, the purpose of which is to collect and divert water from a roof. Picture 1 is shown in the following page that is the paper generally covers the topic of roof systems.
Picture 1
The in-‐class activity for this week is an on site visit at the building that is still under construction. It is an apartment building with 9 storeys and 55 apartments, and 75% of which has been completed. Image 1 on the right is the building. It is introduced that the building is mostly made of concrete, but steel is mostly used for the top floor. In Image 2 shown below, we can see that masonries are used to build the inner walls, and the masonries are hollow inside maybe because it can leave space for steel and concrete to reinforce walls. Also, there is an opening Image 1 framed with timbers in between the wall, which is most likely to put a door in the future. The opening is necessary Image 2
On the ceilings in every floor, there are main components attached with it, such as water pipe and electric wires. Image 3 on the right, shows how and where the systems are being located. Some pipes are made of copper to transfer gas and water to every storey from bottom to the top. On the other hand, sewerage pipes direct wastes from the top down to the underground sewerage system.
Image 3
In the following images, here we come to one of the rooms.
Image 4 Image 5 Image 6 Of all these three images, we can see that the room is decorated by a layer of plastic board on ceiling as well as the inner wall. In Image 4, we can clearly see through the opening on the ceiling, there is an access panel and some service components that have been mentioned above. In Image 5, the fire sprinkler head is installed on the ceiling, and this is to meet the fire rating 90/90/90. In Image 6, the wall that we can see wires go through, there is also fire rated wall system about the wall.
In Image 7, we see that the window doorframe is made of aluminum and galvanized
steel,
as
this
metal
is
advantageous in several aspects, such as lightweight, corrosion resistance, ductility and recyclability. Besides, the window door is sealed with rubber, in order to prevent rainwater from leaking into the apartment. Image 7
Image 8 is taken in a stairway where we can see there are sheet steels underneath the concrete stair; it is said to be the concrete formwork that hold the shape and when the concrete dries out, the sheets will be removed.
Image 8
The image on the left shows the floor system as well as the ceiling. It is rather to be a two-‐way slab that there are reinforcing steels in between the concretes; also, they are precast concrete that pieces of concrete plate are ‘glued’ to become the floors. Moreover, there is steel structure built below the floor system, where the gap in between will be placed pipes and wires; and the ceiling will be made by attaching plastic board underneath the Image 9
steel structure in order to make it look better.
The image on the right is taken in the ninth floor of the building, which is also the very top floor of it. The structure here has very big differences from the other floors, in terms
Image 10
of the materials used. Steel framing is clearly seen in the image, they are painted in yellow because it helps protect the steel from corrosion. Moreover, the roof system is rather to be double span, that there are thick steel joists placed horizontally below the steel channels; also, it is said that the span for the steel joists is 12 meters. To be more specific, it is galvanized steel roof that refers to the fabrication about the roof. More images are shown below about this floor.
Image 12
Image 11
In Image 12, there we see diagonal steel strap bracing welded to studs and runners, and the secure strap connection to stud and runner with a steel gusset welds. The purpose of this is an extra support for the roof structure. Also, we also see access panels that connect to kitchens, bathroom etc., as well as downpipe vents, sewerage and the water pipes for water service.
The Image 13 & 14 show that the surface of the very top roof system, it is said to be the plain plate form that has 2 degrees sloping, so that it could catch more rainwater. In order to prevent the
Image 13
corrosion from the metal sheets, they are already coated and also more protection works are done, for example, there are three gutters in different locations to direct the water down to the ground sewerage, so it
Image 14
means there are different output to distribute rainwater; it is connected to the white box shown in Image 15, the hole of which is extra access when too much water in the gutters. Moreover, flashing is also another work to protect steel sheet from corrosion.
Image 15
This
is
one
of
the
apartments that locates in the eighth floor, here we see the concrete column near the guide, this is one of
the
column
that
support the floor system above. Moreover, there
Image 16
are the stocks of the wall materials that are up to the standard of fire rating. Walls will be built on where the yellow steel frame structures are, so that the boundaries will be clearly settled and also to prevent noise from one apartment to another. In this image on the left, there are roof trusses that support the roof in some ways, divert the force to the walls nearby. Image 17
Image 18 shows there is a timber placed in the gap of steel doorframe, it is acting as a joint as well as a kind of reinforcement to hold the opening firmly.
Image 18