R esults show that the modified cement with good durability, small expansion and low alkality can be made by use of gypsum and zeolite modifying alumina cement.
Zircon is similar to quartz, both in its chemical structure and in its durability, they both stick around a long time after other minerals weather away.
While our modern concrete has the strength to hold up very tall buildings and heavy infrastructure, it cannot compete with the endurance of these ancient materials.
True Invisibility Cloaks, though rare, exist in this world of ours; however, the story makes it clear that Death's Cloak is of a uniquely durable nature.
The reinforcing steel is tightly wrapped in concrete, effectively preventing corrosion of the steel, increasing the durability and reducing the maintenance cost of the skyscraper.
Modern greenhouses, on the other hand, only came about with the ability to mass produce thin glass panes and iron structures durable enough to hold everything in place.