15 DAYS THAT CHANGED THE WORLD (AT LEAST CONSTRUCTION WORLD)
We got this article from our esteemed friend, Gerardo Gusukuma, an outstanding construction engineer who I met in Lima, Peru, recently. He has some great ideas here and we share them with you. He describes Zang Yue's construction projects, which are amazing if you can look at them on the U Tube link in this article. We also have a video link of a 10 story building in India, using Zang Yue's ideas, that went up in 48 hours, near the end of this article. Feel free to forward this article to your associates, with our compliments. Click this for the link: GLOBAL PERSPECTIVES.
How much time erecting a building can take? A good method to get that amount is to consider roughly 1 month per floor. So, if you plan to construct a 30 story building, it will take you 30 months or 2 years and a half to carry it out, which could be less but as an estimated is Ok.
Now watch out what the Chinese are doing and of course how much time they took in this video called “A 30 story building in 15 days”
“A 30 story building in 15 days”, the guy in the photograph, Zhang Yue, got famous as the responsible of this big achievement. In an interview, when asked by Lauren Hilgers, if he had decided to start a construction company, apart from his original air condition business, Zhang Yue said: “It’s not a construction company. It’s a structural revolution.”
And we agree.
His success is based on redeveloping the three phases of constructing a building: Engineering, Manufacturing and Erection.We could explain it as follows:
1- Engineering: Design concerned about construction
Considering Engineering as the task of creating or designing the building in drawings, technic files, scope, plan of work, etc., we can realize that designers are not concerned for construction process simply because they are not going to erect the building, that is why they deliver only a basic engineering (drawings, schemes, etc.) enough to complete the construction of the building but insufficient in order to carry it out without problems. If during construction process an issue that involves design shows up, it is solved on the road and, depending on how important modifications are, a well performed building could turn into a behind of schedule project.
The new designers must be involved in construction process too. They are aware that any failure in alignment of holes for bolts would delay the erection process, this is avoided when engineering has got a high detailed level, and fortunately that precision could be achieved nowadays by using 3D Design Systems or BIM (Building Information Modeling) which allow them to make drawings ready to manufacturing and 3D models if required in complex cases. With these new methods, designers apart from checking the structural performance of the building, are able to run a simulation of the erection process, making sure this way there won’t be any interference or defect that can paralyze the construction. They construct two times: first in the computer and then in reality. You can see it on this video:
In addition traditional design leads to use the minimum amount of materials, as well as the cheapest, because the owners always are looking for saving money.
In regards to cost of materials, concrete has become the cheapest since many decades ago. Concrete offers several advantages but is a very slow-placing material: before placing concrete you need to place steel rebars, to erect the formwork and, finally, to pour the concrete, which is usually limited to a certain volume for several reason but mainly geometry. Besides, it is mostly required to wait some more days, until it gets the design strength, to remove the formwork and to work on its surface. Precast concrete is more useful to construction process but it does not ensure being monolithic which is required for any building.
On the other hand steel is more expensive than concrete but offers many advantages over, especially when thinking about a fast erection. Steel pieces can be mass produced, easily connected whether by welding or by bolts during the erection process and start to work immediately after fixed.Zhang’s building was mainly made from steel, a little of wood but not any concrete. And furthermore, in regards of Environmental issues, steel is better than concrete as building material (see this research of Timothy Werner Johnson). Are we about to see the death of concrete? I don’t think so but there will be depletion in its consumption, in the future concrete will be limited only to massive projects like dams or big foundations for steel structures.
In sum, while traditional design is made to save money by reducing materials, on the other hand this new engineering is leading to save money by reducing manufacturing and erection times.
We bet on the latter.
2- Manufacturing: Mass production
Manufacturing in construction is less than in other productive activities, unlike other industries, in building erection the pieces are assembled in its final location, because the final product cannot be moved as if it was a car for example. A building is constructed from the basement or first level up to the top, it means if you haven’t finished the first floor you can’t start the second one or if you haven’t finished the second level you can’t start the third one and so forth. This is a big constrain, considering that we have all the resources to manufacture any floor we wish. Physically we could describe this as a Vertical Production Process.
On the other hand, the most efficient way of production continues to be the assembly line invented by Henry Ford almost 100 years ago. In this industrial process, materials and consumables are carried by conveyor belts through several work stations until obtaining the final product. Physically we could describe this as a Horizontal Production Process. Charles Chaplin realized better than anyone, and his film Modern Times shows comically how fast assembly line works.
Zhang realized that Horizontal Production Process is more efficient than Vertical Production Process because it allows floor massive production, while the latter is a one by one production. He performed Horizontal Production Process in manufacturing of buildings pieces, he manufactured 30 stories at the same time, and kept Vertical Production Process only when it couldn’t be avoided, it means during erecting process. Comparing with traditional way of construction, we could say he builds 90% of the building in assembly line and keeps the 10% left over to be erected as usual.
Well played again.
3- Erection: Continuous process
As stated in first paragraph changes in Engineering and Manufacturing come also from redeveloping Erection process, in order to make it a continuous process. Only a perfect design can leads us to a non-interruptions erection process. On these times, times of 3D models and BIM, good is not enough, it is required to be perfect. The proof is there, his design was as perfect that they didn’t have any interruption during those revolutionary 15 days.
In addition, traditionally erection used to be a manual process: workers placing bricks, steel, formwork, etc. And that was because of the also traditional in-situ manufacturing process above stated. Now as we are manufacturing the floors (not the entire floor but big packages of each one), they cannot be placed by hand, so they must carried by crane to their final locations making this process a lot more efficient. The workers, which will tend to be less now, will be only to make the connections: bolts, nuts, maybe welding, no more else. Here planning is important too. Organizing day-night shifts (what an important point, builders don´t realize they are wasting one shift by working only during the day), hiring suitable equipments, coordinating transport from factory to site and keeping safety and quality high patterns were important as well.
In sum, when Engineering and Manufacturing have been made under Zhang’s philosophy, Erection process is the easiest thing in the world, don´t waste your time on that, not more than 15 days. For example a group of Indians took only 48 hours in a 10 story that is also featured on U Tube.
We are seeing a revolutionary step in construction, and it is coming from China and India. This should be no surprise if you have visited those countries recently. The fact that we get this story from another extraordinary engineer Gerardo Gusukuma in Lima, Peru, is also interesting. There is a profound energy, especially among the young people, of the world. I called them the "Connected Generation" or the 'Global Generation' in my book FLOWERS FACING THE SUN, several years ago. We believe and encourage this "connected generation" to lead the world, not only in technological and engineering advances, but to a world of Global Peace and understanding….Ben B. Boothe, Publisher http://www.bootheglobalperspectives.com