I went to Home Depot and they said there was no such thing, all cement bags have rocks, is this true? If I went to Home Depot to buy a bag, what would it say on the bag?
I guess by rocks you mean aggregate, i.e. small stones. You can mix concrete without aggregate but it's not as strong. Pretty much any time you mix concrete it will have aggregate in it and you should be using rebar or wire mesh to reinforce it.
cement has no aggregate. there is type I type II and type N. these are usually used for brick mortar and parging of brick walls. Then you have concrete that has stone and is used for structural work such as walls, sidewalks and foundations. I used to work at a contractors supply house and at Home Depot, if the person at HD told you there was no such thing go to the Pro desk and ask them you are looking for portland cement.
Table 1: Typical Concrete Mix Component Percent by weight Portland cement 12% Sand 34% Crushed stone 48% Water 6%
Cement is a term specifically used to describe one ingredient of either concrete or in other flavors sand mix or mortar mix. Its full name is portland cement to differentiate it from any other type of glue which may also be referred to as cement. Generally you select any product based upon the application. Rocks add strength to a concrete mixture. You have a reason for not wanting any rocks. If you are trying to glue bricks or cement blocks together you would use a mortar mix. (Although if you were not concerned about fire I have seen a quick wall with cement blocks and construction adhesive.) If you are trying to fill in a smallish hole in a sidewalk you might use a sand mix or a concrete leveler. If you are trying to fill in low spots in a sidewalk you might use a concrete leveler like Top Bond.If you are trying to fill in around rods or handrails you might use an anchoring cement. If you are trying to fill in a hole or crack against water you would use a hydraulic cement. For top coats on walls you might use a mortar mix or several other commercial preparations. Of all of these the hydraulic cement has the finest particles with a top coater like topbond coming a close second. It is virtually clay that hardens quickly. If you go back to the depot instead of a masonry yard let them do what they know best: describe their products. Just tell them what you are trying to do. There are also preparations that use a non mineral based filler instead of sand. I recently saw very light cement blocks in Europe, but they have a problem of soaking up a lot of water. Structo-light might be one such product.
