Stuart,
Thank you for bringing up this topic. I believe it has a big future but with matching material research. The mass production and construction objectives of precast concrete, in Europe, go back long time ago; well before 3-D printing. Now, 3-D printing fits those objectives best, but the material has to adapt to it: placing reinforcing bars is not good fit for 3-D printing, but fibreglass-reinforced concrete (other fiber-reinforced?) would be more fitting. The new material needs to take tensile stresses in a homogeneous way.
As to historical background of mass production of housing units, that was a European Precast concrete technology long time ago:
- That system was used, in the mid 1960’s, to build a new town next to Tabqa Dam on the Euphrates River in Syria. A Hungarian engineer introduced a fully integrated precast concrete, mass production, plant to that area. That system became a must read to every new engineer in that country. Since, he was my Professor, who supervised my Diploma Project; I was hooked on precast concrete since then.
- A similar system was used, in the early 1970’s, to build a new town near the oil fields at Hassi Messaoud, in Algeria. Its chief engineer was my supervisor at an international engineering firm in Lebanon. It was a pity that I just missed working on it.
- Habitat 67, or simply Habitat, is a model community and housing complex in Montreal, Quebec, Canada, designed by Israeli-Canadian architect Moshe Safdie. Habitat 67 is widely considered an architectural landmark and one of the most recognizable and spectacular buildings in both Montreal and Canada. (picture below)
When I came to Canada, I was lucky to be “adapted” by the guru in precast concrete, the late Thomas Ecsedi. However, to my surprise, there was nothing close to any of the above; there was nothing like Safdie’s anywhere in sight. Design was based on more project-specific basis. There was some repetitiveness of units, but not without individual differences here and there, to fit the overall structure. In some cases, precast unites were just one-of-kind master-piece such as the example below, AARP Headquarters-Gate 2, Washington, DC (by Pre-Con, Ontario). I grew to like this North American way of Precast Concrete.
Now, we are back to square one with 3-D Printing. Is North America ready for its kind of Architecture?
That’s beyond me.
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Neil Kazen, M.Eng., M.Sc., P.Eng.
FASCE, FCPCI, FEC,
Retired Structural Engineering Manager, Transportation Division, SNC-Lavalin
Toronto, Ontario, Canada
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Original Message:
Sent: 07-10-2019 07:37
From: Stuart Walesh
Subject: Sketching/Art in Engineering Professionals of Today
Neil:
Sorry to go off on a tangent, but you mentioned a growing interest of mine -- precast concrete.
If you care to share, what do you see in the future of large-scale 3D printing becoming very important in the precast concrete industry?
I am finding R&D projects in which large-scale 3D printing with various forms of concrete is being used to "print" houses, bridges and components of them, components of other structures, decorative panels, etc.
Original Message------
Chad,
That reminds of my years in the Precast Concrete industry. When inspecting construction sites, I take closeup photos at perpendicular view , with a right-angle scale placed within the view. The two-directional scales are to allow for correction due to possible inclined angle.
Together with the little site- notebook, I could recreate a detailed picture when I'm back in the office. As you said, the weld width could be determined and authenticated to a mill. Such reports proved very useful in claims, putting me on solid ground.
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Neil Kazen, M.Eng., M.Sc., P.Eng.
FASCE, FCPCI, FEC,
Retired Structural Engineering Manager, Transportation Division, SNC-Lavalin
Toronto, Ontario, Canada
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