similarities between modern cement and ancient cement
Answers
First off there's a wide variety of modern concrete. The portland cement part of concrete is the same but what you add to it and the water/cement ratio can vary quite a bit depending on what properties you want out of your concrete.
Roman concrete had volcanic ash added to it. That's similar to modern concrete that has fly ash added to it. Pozzolan (Roman volcanic ash) might wind up being superior to modern fly ash for a couple of very boring reasons involving cement chemistry that I will skip here.
They've known about that both from chemical analysis of Roman cement and from records that survived from Roman times.
Answer:
SIMILARITIES:- Both are used for construction work.
DIFFERENCES:-
Modern cement - Modern cement is made from silica (sand), alumina (aluminium oxide), lime, iron oxide and magnesia (magnesium oxide).
Ancient cement - Aqueous cement is made by mixing volcanic ash in moistured lime.