"Iran ‘smart concrete’ to protect N-sites from US bunker busters" (PressTV-Iran)

Not the same concrete as that inside Ahmadinejad's head evidently:

As tension escalates between the US and Iran, American officials are increasingly concerned that the use of “smart concrete” may render Iranian nuclear sites impervious to US bunker-buster bombs.

An article published by Aggravate Research website, which represents Aggravate Industries, stated that due to Iran's geographical situation, the country is under constant threat of earthquakes.

As a result, the website said, Iranian engineers are very good at developing “ultra-high performance concrete” (UHPC) which is among the toughest and most rigid building materials in the world.

It added that the new Iranian concrete, made on an indigenous formula, is now a major concern for Washington in addition to Iran's uranium enrichment work, whose technology has been also indigenized.

“Unlike conventional concrete, Iranian concrete is mixed with quartz powder and special fibers - transforming it into high performance concrete that can withstand higher pressure with increased rigidity,” the article stated.

Due to its combination, the new Iranian-made concrete is an excellent building material with peaceful applications like the construction of safer bridges, dams, tunnels, increasing the strength of sewage pipes, and even absorbing pollution.

However, the article said, like any dual-use technologies that carry both civilian and military applications, the UHPC can also be used to protect underground facilities from bombardment, which could pose a real headache for military endeavors into Iran.

According to the article, US Defense Secretary Leon Panetta recently expressed his concern that in case of a real conflict, the American bunker busters may not be able to penetrate Iran’s deepest bunkers should the UHPC be employed for military purposes. [...]