Stainless steel rusts or didn't you catch that part? Glass in a landfill will devitrify rather quickly, probably faster then if it was on the surface. Look at a bottle that's been in the dirt for a while. See that whitish coloring on the surface? That's the glass beginning to break down. After enough time has passed it will fall apart and you will be left with a white powder as the glass devolves back into its constituents.
Here's a little article on Roman concrete and yes it was significantly better then the concrete we use today. They were able to build mile long arched aqueducts without having to use expansion joints. Try doing that with modern cement, ain't gonna happen.
Mayan cement was much better then ours as well.
See you need to read some history my friend. It's amazing what you can learn when you crack a book.
"Two thousand years ago the Roman Empire built concrete structures that still look as though the concrete was just poured. Modern concrete structures not even a century old are crumbling and many of them are already in ruins. What is the difference between the concrete the Romans used compared with modern Portland cement based concrete?
The Roman engineers did not have any thing resembling modern Portland cement that was invented by an English mason in 1824. It was literally something he cooked up on his wife's kitchen stove. It was made from a mixture of clay and limestone that was ground into a fine powder. The resulting cement was in the form of a clinker that had to be ground so fine that it would pass through a mesh that water would not.
Roman cement was made from two simple ingredients that were available in abundance: limestone and volcanic ash. There are plenty of volcanoes in Italy especially around Naples and Rome to supply the ash. Limestone was plentiful in the Dolomites a mountain range making up the backbone of Italy.
The most important ingredient was a good quality of white limestone that the Romans subjected to a heating process that drove of carbon dioxide leaving behind calcium oxide. This is familiar as Quick Lime. When it is added to water the heat generated by a chemical reaction is enough to bring the water to the boiling point. It also leaves behind a product called hydrated lime that was stored in amphora until use. This material mixed with clean river sand produces mortar used to set stones and brick."
Roman Concrete Compared to Modern Concrete - Associated Content from Yahoo! - associatedcontent.com
