Posted on 05/25/2008 7:44:51 AM PDT by DeaconBenjamin
These pictures are from Der Spiegel
There goes our cement. We should double the price of our cement and stop buying their products. A perfect time to set them back 100 years in their quest of becoming a world power.
Damned damaged dams!
(sorry, couldn’t resist) =P
IB4TJD
When Sri Lanka is bailing you out, you know you’re in trouble.
It’s quite probable that in order to make the concrete more pumpable too much water was added. Knowing how low-bid contracts have worked in the USA, I’m pretty certain contractors and sub-contractors (as well as Communist Party cadres) on these projects skimped on the quality of concrete, reinforcing and even curing time.
Not too sure if vermiculite can be used in this situation but patching with concrete isn’t going to do too much unless it can cure in a relatively dry environment.
JD?
Lawyer?
Cement is only one component of concrete. Concrete, in general, is relatively inexpensive; that’s why it is used in so much of the world’s construction. It’s the price of deformed (the ones you may have seen with the little ridges) steel reinforcing bar that has really been going up. Epoxy-coated re-bar, which is longer-lasting, is even more so.
Please keep in mind cement can be used as a finish material but it is reinforced concrete that has significant structural tensile and compressive strength.
During a time o war hitting all 70 dams at the same time would just about end a war.
The pictures and facts coming out of China is amazing. That society is changing at an amazing rate.
That next to last one look like a fualt, right down the middle of the dam.
yikes.
Ironically, the Chinese army is showing their stuff; effective and competent...very effective transport infrastructure....the Chinese military is a formidable force.
Has anybody thought about those rumors of the folks that claimed that the building of the Three Gorges dam would put unknown stress on a fault line possibly creating earthquakes?
Irony indeed, a nation that will collapse by its own ideas of expansion.
As I mentioned in my previous post, flowable concrete (not to be confused with cement, which is a binder used in the concrete mix) can have too much water. However, additives can make a low-slump concrete more flowable without too much water. As long as the concrete is properly vibrated once placed, separation of aggregate (usually gravel and sand) shouldn’t be a problem.
Your concern is well-founded; I have seen formwork removed and all the aggregate was sitting at the bottom - there were huge voids in the concrete surface, which meant there was no aggregate in the top of the wall. The consequence of this kind of wall means that there is no material, like gravel, “locking” around the reinforcing bar in the wall. The concrete at the top of such a wall is more likely to crack, allowing moisture in to oxidize (rusting) the re-bar. This in turn leads to spalling of the surface, allowing the smoother, denser exterior finish to expose a more absorbent core, which leads to the ultimate demise of the wall.
During the civil war they called you a carpetbagger. Who would think that someone would be so unashamed as to publicly announce it.
Good one!
What the Chinese nationals find interesting is that the government is talking about what its army is doing. Such public discussion used to be very off limits.
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