For concrete done right, use Roman recipe

Some Roman concrete structures have been around 1,200 years or more. And, archaeologists say the Roman stuff is ecologically friendlier.

http://www.sciencedaily.com/releases/2013/06/130604135409.htm

From www.gatesofvienna.net and

http://www.archaeology.org/news/960-130607-concrete-rome-baiae