Self-healing materials could be pretty cool if we get them figured out.
I appreciate the brief dalliance into cold welding between metallic pieces in space - something I've posted about before.
And I appreciate Steve Mould, of course, who sadly keeps his humour (British, natch) mostly in check for this video.
I'm approximately a million hours away from being a structural engineer, but I think I could look at the cracks shown in the video at 6:49, 10:47, and 16:20 and say that maybe they shouldn't be going ahead with moving the bridge into place.
I never would have thought of the shifting forces during the movement of the bridge from its initial fabrication location, but the need to constantly restress the concrete with each move is fascinating. I would think that would require the concrete to be stressed and stressed and eventually over-stressed.
I've been watching videos from Brick Immortar of late and will have another one from the same channel next week, but I could pick probably any of these videos and post them here. They all seem to analyze famous engineering failures, quickly recap the incident, then summarize the causes of the failure.
This one is one I'd heard about and that I've seen discussed as a famous case of plans being adjusted without proper checking to see if that seemingly minor change would be problematic. This is, however, the first video on the incident that I've seen discuss that the original design would have been problematic over time as well.
I'll admit that I do wish today's video would do a little better job of telling what porcelain is rather than just telling why it's so labor intensive to make.
So I went looking around the intertubes to find some definitions of what porcelain is.
From wikipedia...
Porcelain is a ceramic material made by heating raw materials, generally including kaolinite, in a kiln to temperatures between 1,200 and 1,400 °C (2,200 and 2,600 °F). The greater strength and translucence of porcelain, relative to other types of pottery, arise mainly from vitrification and the formation of the mineral mullite within the body at these high temperatures.
From Britannica...
Porcelain, vitrified pottery with a white, fine-grained body that is usually translucent, as distinguished from earthenware, which is porous, opaque, and coarser. The distinction between porcelain and stoneware, the other class of vitrified pottery material, is less clear. In China, porcelain is defined as pottery that is resonant when struck. In the West, it is a material that is translucent when held to the light.
From Webster's...
a hard, fine-grained, sonorous, nonporous, and usually translucent and white ceramic ware that consists essentially of kaolin, quartz, and a feldspathic rock and is fired at a high temperature
From Far and Away...
Ceramic is a broad term for various materials that are made by firing clay or other mixtures at extremely high temperatures. Generally, it includes products such as pottery, tiles, and cookware. The surfaces of ceramic can be painted or glazed to create different finishes and styles.
Ceramics are usually broken down into three categories: porcelain, stoneware, and earthenware.
Porcelain is denser than stoneware and earthenware, which makes it the strongest type of ceramic. In addition to its strength and durability, porcelain also has an extremely smooth surface that lends itself well to decorative treatments such as hand painting or airbrushing. Porcelain is also the least porous type of ceramic material, which makes it ideal for use in bathrooms or kitchens where watertightness is important. Earthenware is the softest type of ceramic material and can be very delicate in nature. It also has a tendency to absorb moisture easily.
Earthenware pieces tend to be thicker than their porcelain counterparts due to their lack of strength and durability. As a result, they are often produced in simpler shapes with fewer decorative details since any intricate detail may be too delicate to survive regular use or exposure over time.
Stoneware falls somewhere between porcelain and earthenware in terms of strength and durability making it a popular choice for everyday items like plates or mugs since it can withstand some wear-and-tear but isn’t overly fragile like earthenware pieces tend to be. Stoneware has been used throughout history for many types of items including storage jars, jugs, figurines and table services sets due its versatility in design options depending on the levels at which it’s fired during production processes.
...
Porcelain is a fine-grain ceramic material made from kaolin, a white clay mined in various parts of the world. It is used for tableware, tiles, and other applications where strength, hardness and stain resistance are desired.
Porcelain has an extremely low porosity—it is nearly waterproof—and it is considered to be thermal shock resistant. It can withstand temperatures up to 1800 degrees Fahrenheit and it does not react with chemicals in the same way as other ceramics. Porcelain can accept a wide variety of decorative glazes and finishes, which makes it ideal for many applications.
When comparing porcelain to its relative ceramic, there are some key differences to consider:
Porcelain has a finer grain than ceramic and its ingredients go through more processing before they can be used as a material choice.
Due to its high degree of density, porcelain is more durable than ceramics but it also costs more because of the processing involved in producing the material.
So, there you go...
