Mathematics, and the case of the missing concrete.

[jschurchin]

First off let us assume (yeah, I know) a few facts. First, there was 450,000 cubic yards of concrete used in the construction of the towers. Second, there was 200,000 tons of steel used in the construction.
Each tower weighed in at 500,000 tons for a total weight of 1,000,000 tons. We know that there was 200,000 tons of steel, but how much does concrete weigh?

I did a google search asking that same question, answer: wet 3,900 lbs per cubic yard. Cured 3,500-3,700 lbs per cubic yard. So a little math 450,000*3,600=1,620,000,000lbs or 810,000 tons. A little more math 200,000(steel)+810,000(concrete)=1,010,000tons divided by 2 towers equals 505,000 tons. Pretty close huh?

It is safe to assume that all of the concrete was used in the construction of the towers.

Now, how much concrete was used on each floor? We know the dimension's of the building were 208'x208'. Since concrete is measured in cubic yards we need to convert this to yards. 208 divided by 3 equals 69.03 yards. Now how thick are the floors? I used an average 4 inches for the floor and to convert that to yards we divide 4 by 36 resulting in .111. Now to figure cubic yards 69*69*.111=528.471 cubic yards per floor. 110 floors per tower 220*528.471=116,263.620 cubic yards.

We are missing a whole lot of concrete. Where did it go? Christophera might have the answer.