15 DAYS THAT CHANGED THE WORLD

 

After the video “A 30 story building in 15 days” he 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 air condition business, Zhang Yue said: “It’s not a construction company. It’s a structural revolution.”

And I agree.

His success is based on redeveloping the three phases of constructing a building: Engineering, Manufacturing and Erection.

I could explain it as follows:
 

1- Engineering:  Design concerned about construction
 

Traditional structural design leads to use the minimum amount of materials, as well as the cheapest, because the owners always are looking for saving money. So, structural and facilities designers are not concerned for construction process, that is why they deliver only a basic engineering (drawings, schemes, etc.) enough to complete the analysis of the building but insufficient in order to carry it out. 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.

In regards to cost of materials, concrete has become the cheapest 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. In addition, 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 has disadvantages too.

The new designers are 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 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. You can see it on this video:
 

 

On the other hand steel is more expensive than concrete but offers many advantages over, specially 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

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.

I bet on the second one.

 

2- Manufacturing: Mass production
 

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.

On the other hand 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. Physically we could describe this as a Vertical Production Process.

It is easy to realize that Horizontal Production Process is more efficient than Vertical Production Process because it doesn’t have constrains involved in the last one.

Zhang Yue has realized this perfectly and performs Horizontal Production Process in manufacturing of buildings pieces, and keeps Vertical Production Process only when it can’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.

Charles Chaplin realized better than anyone, and his film Modern Times shows comically how fast assembly line works.

 

Well played again.

3- Erection: Continuous process
 

Actually changes in Engineering and Manufacturing come 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.

Planning is important too, because while in an usual building the most of the stores is typical and are divided into sectors, which run in parallel up to the last level; he has divided the stores into pieces, it means finished blocks which only have to be placed and well connected to get the building. Organizing day-night shifts, 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, no more than 15 days.

For example these Indians took only 48 hours in a 10 story building.

 

Thanks Zhang it doesn’t sound impossible, not any longer.