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.
Best Answer: Concrete is a structural material which consists of Portland cement, aggregate (sand and rock), and water (to make the chemical reaction called hydration occur.) Concrete can sometimes contain other substances, such as fly ash from industrial smoke stacks, which can change its properties.sually when a batch of concrete is ordered on a job site it is specified to be of a specific compressive strength -- 4000 psi, for instance. When the concrete comes to the job site in a ready-mix truck, the contractor places some of the batch in cylinders which are 6 inches in diameter and 12 inches in height.