Vietnam is bordered by China to the north, Laos to the northwest, Cambodia to the southwest, Thailand across the Gulf of Thailand to the southwest, and the Philippines, Malaysia and Indonesia across the South China Sea to the east and southeast.[d] Its capital city has been Hanoi since the reunification of North and South Vietnam in 1976, with Ho ...
Cement. 1  Cement is a binder. Similar to flour in a recipe, the purpose of cement is to hold the other materials together. 2  Concrete is a composite of aggregate (such as sand or gravel), cement, and water. Itâs like a cookie. 3  The basic composition of mortar might seem similar to concrete, but what really sets it apart is how it is used.
âPortland cementâ is the generic term for the type of cement used in virtually all concrete. In its simplest form, concrete is a mixture of paste and aggregates. The paste (portland cement and water) coats the surface of the aggregates. Through a chemical reaction called âhydration,â the paste hardens and gains strength to form the rock-like mass we know as concrete.So, there is no such thing as a cement sidewalk; the proper term is concrete sidewalk.