This is a wonderful option for providing a level bottom over rough or dusty terrain. Because lean concrete utilizes less cement, it is employed in fills or under foundations to protect the building from the earth. Lean concretes also make excellent driveway and walkway surfaces.
Concretes are materials that are mixed with water and sand or gravel and then poured into forms to make shapes suitable for use on roofs or as roadbeds. The ingredients of concretes include fine aggregate (gravel), coarse aggregate (dirt), water, and cement. Concrete can be molded into various shapes and cured into durable products that can last for decades if properly constructed. It is used in buildings as flooring, walls, and ceilings and in roads as pavement.
Concrete has many advantages over other construction materials including its light weight and ability to provide sound insulation. It is also inexpensive and easy to work with. However, concrete requires care and maintenance to ensure its longevity. It is important to clean up any leftover materials from concrete projects because they will attract animals which may cause damage to your home or business. Animals also find concrete floors unattractive and will often try to avoid them by walking on the side opposite the house or office building.
If you want your project to look good long after we've gone, use concrete.
As far as the lean concrete is concerned, it serves no purpose other than to create a flat surface for the insertion of rebars, hence there is no need for curing. The same goes for plain concrete. It needs to be cured to make it strong enough for its intended use.
Concrete that is too soft requires more time to cure than soft sand or clay, which means that it can be used immediately after mixing. Concrete that is too hard requires less time to cure than softer materials, so it can be used later after some time has passed. Usually, concrete cures in three days if the temperature stays below 90 degrees F and there is adequate moisture present, but this can take up to six months at temperatures above 100 degrees F or when it rains often. Curing concrete also helps prevent the growth of bacteria that can cause disease.
The type of cement used in concrete affects how it cures. Ordinary portland cement will keep the concrete solid until it reaches 120 degrees F, at which point it begins to melt slightly and then turns into a harder stone-like material. This is called "cured" concrete and is suitable for most applications where strength is not an issue.
Backfill beneath concrete flatwork along foundation walls should be done using a uniformly sized granular material. Some fill materials, particularly spherical stones like pea gravel, self-compact. "I propose using open-graded granular material," Tull explains. "This means that there will be an upper layer of coarse material which has been graded to allow water to drain away from the foundation wall." The lower part of the hole will be filled with a finer grade of material. This creates an air space between the foundation and the ground below which allows for some movement in response to temperature changes without causing problems such as cracking or leaking.
Concrete flatwork (the surface upon which a floor is laid) requires special attention when backfilling underneath it. If the hole for backfilling contains any sharp edges they will eventually show up as cracks in the finished floor. To prevent this, use a backhoe or other mechanical digger to excavate a large enough hole to completely cover the flatwork with gravel or other filler material. Then smooth out any rough edges on the flatwork with a power edger or other tool before pouring the concrete.
It is important to keep track of how much concrete was used for the flatwork so you do not run out before finishing the rest of the house.