Yes, in about a month, fine cracks should disappear. While shrinkage cracks can appear on the surface within hours of pouring concrete, it takes a full month for new concrete to fully settle. Concrete cracking can appear at any time, even on a year-old slab like yours. The base under the entrance may not have been compacted properly, and that may have caused the concrete to sag or settle slightly and therefore crack.
Or some water may have flowed under the slab and eroded or consolidated the base to the point where the concrete was not supported. The concrete may also not have been properly formulated, placed, or finished and cured for its greatest strength, so the weight of automotive traffic could have contributed to cracking. There are other reasons for cracking, but one explanation takes much longer; and from your description I think you are witnessing shrinkage cracking. Cracks that crack are very fine surface cracks that resemble cobwebs or broken glass.
When the top of a concrete slab loses moisture too quickly, cracks are likely to appear. While unsightly, cracked cracks are not a structural concern. As a general rule, any concrete slab longer than nine feet will crack. I'm sorry for one of those who say that the floor in their basement never had cracks.
You probably haven't noticed them. The chemical reaction, which causes concrete to move from a liquid or plastic state to a solid state, requires water. Concrete suppliers sometimes add water to make working with concrete easier, but this weakens the concrete. In addition, concrete poured in mid-summer will have more cracks than concrete poured when it is colder.
He investigated the crack and told us that it was a normal function of cement to crack like this; due to the displacement of the soil, the cement does crack. Let us know if you need more information like this to help you manage customer expectations for future concrete maintenance needs in a home they are considering. This ground movement caused by the freeze-thaw cycle is a huge factor contributing to concrete cracking. In general, cracks wider than a credit card and running through the depth of concrete are structural in nature and could be a sign of more serious problems (see Evaluating Concrete Crack Repair).
Not only does it facilitate the curing process, but it also protects concrete from dirt, grease and other stains. Understand what your contractor is doing with respect to each of the items listed above and you will get a good concrete job. Concrete cracks may seem scary at first, but they are common in almost every home that has a concrete floor. A good rule of thumb is not to dig more soil than is necessary to accommodate the desired depth of concrete and a few inches of gravel.
When properly installed, concrete is one of the most durable and long-lasting products you can use in your home. Crusting cracking generally occurs during the concrete stamping process, which is a way of adding texture or pattern to concrete surfaces. Some contractors like to place a layer of sand over the vapor barrier, but most have been adapted to place concrete directly on a heavy-duty vapor barrier. The following information is useful for diagnosing cracked concrete, but if you want expert input, contact a nearby concrete contractor for an in-person evaluation.