The two classifications are not opposites. There are concrete nouns (physical things) and abstract nouns (concepts or feelings). There are proper nouns (names) and common nouns (unnamed things). Nouns can be both concrete and proper: Cleveland is a concrete, proper noun - a city in Ohio. St. Louis Cathedral is a concrete, proper noun - the name of a church. Voltaire is a concrete, proper noun - the name of a famous writer.
A wooded frame is made into a shape, for example a stair case, and then the concrete is poured into the frame. After the concrete has set, the wood/shuttering is removed, leaving a solid concrete shape. Steel bars are added into the concrete as it sets to give the shape more strength. Vague description but that the general idea of it, hope it helped.
Yes you can use wood stain on concrete but it will not penetrate the concrete, it does look nice and you can use different shades together. To keep the stain on it use a concrete sealer in a couple coats, it will give it a shiny wet look. I have tried it with fake wood only because where I live I can't get concrete stain. And it looks great.
Rebar is used to give strength to masonry and concrete constructions. Masonry is this case is concrete blocks. Concrete, block or cast in place, is good for compression forces and not tension. Steel is good in tension or tensile forces and not compression. By combining the constructive elements of concrete with steel, thus reinforced concrete, you get the strengths of both in one medium.
The Colosseum was made of stone and concrete, not brick and concrete. Roman concrete was not as fluid as modern concrete and therefore had to be layered by had which could give and impression of bricks. The Romans used concrete for the shell of buildings and covered with other materials, such as a layer tuff (a local rock) stucco and, sometimes, marble. For the Colosseum they used large stones because of the massive size of…
For sidewalks and other concrete surfaces, forms may be removed 1-1/2 to two days after pouring and finishing. Concrete "sets" pretty solidly after one day, but give it a little time to get harder, so that you won't damage the corners or surface while removing the forms. Waiting too long can make it difficult to "unstick" the forms from the sides of the concrete. Concrete sets to about 90% of its strength in seven days…
simply workabilty is the w/c ratio in concrete. more the w/c ratio higher the workability and vice versa. and it is true that excess amount of w/c ratio doesnt give proper strength. so workable concrete i.e, concrete with proper w/c is must for good strength. *note: not considering the mix of concrete.