Standard-duty concrete lots needed 7 inches of concrete over a 6-inch subbase using typical design approaches. The revised standard calls for a 5-inch layer of concrete with no subbase. Heavy-duty lots that used to require 8 inches of concrete over a 6-inch subbase now demand 6-inch concrete over a 4-inch subbase. The difference between the two types of concrete is the amount of air in the mixture. Standard-duty mixes are designed to set up more quickly so drivers can move their cars from spot to spot, while heavy-duty mixtures are made with more cement and less sand to make them stronger.
The first thing to understand about what type of concrete you need for your parking lot is its purpose. What will people be driving on it? If it's going to be driven regularly, like in a garage or parking lot of a building, then you should get a quality concrete driveway. These usually last for several years if done properly, and they look good too! Concrete drives are easy to clean and maintain, and they don't cost that much to put down.
If you just want to cover it with a coat or two of asphalt, that will work too. But since this is only occasional use, regular concrete is probably overkill. Asphalt does have the advantage of being recyclable when it gets old or needs to be replaced partway through construction of your garage or other structure.
Finally, there's colored concrete.
The normal thickness of concrete is 4 inches. To properly manage hefty weights, increase this to six inches. Enter the depth, breadth, and length of your concrete footing to find out how many cubic yards and concrete bags you'll need to finish your job.
As long as you follow the guidelines in this article, you should have no problem finishing your project on time and within budget. If you need more than one layer of concrete, it's best to wait for a dry day so the layers will stick together.
The weight limit for concrete is about 20 percent of what a normal load would be. So if you were to pour a slab 30 feet by 60 feet, with a density of 2 pounds per square foot, you could load it with 400 pounds. For example: If you load a truck with 20-pound bags and haul them away every other day for a week, then take a break over the weekend, you'll use up all 400 pounds before you reach 16 feet. You should plan on making at least two passes with the mixer to get an even color and texture across the slab.
If you want to add rebar to your concrete floor, do it after it has cured for at least 24 hours. Then pour another layer of concrete over the top and smooth it out with a float shovel. The steel will keep the wood from becoming exposed once the cement dries.
The amount of concrete required for a 10-by-10-foot slab is determined by the slab's diameter. A 4-inch slab requires either eight 60-pound or six 80-pound bags, while a 6-inch slab requires either 12 60-pound or nine 80-pound bags. The weight of the bag varies depending on the type of cement used.
Cement weighs about 27 pounds per cubic yard. So, if you use standard cement, then 8 inches of 4-inch-thick concrete will require 112 square feet of surface area and 16 inches will require 224 square feet. 9 inches of 6-inch-thick concrete will require 216 square feet of surface area.
The total weight of the concrete required is measured in tons. One ton contains 2,000 pounds. Therefore, one truckload contains 200 yards (180 m) of 4-inch concrete or 300 yards (270 m) of 6-inch concrete.
The density of concrete varies depending on its composition but generally measures around 3,000 to 3,500 kg/m3. This means that 1 ton contains approximately 2.7 million kg or 5.5 million lb.
Concrete has a specific gravity of 0.90. This means that it weighs 90 percent as much water as dry material. Concrete that is mixed with air bubbles will have a lower density because more space is taken up by the bubbles than by the dry material.
According to FAO, concrete blocks are typically formed of 1:3:6 concrete with a maximum aggregate size of 10 mm or a cement-sand combination with a 1:7, 1:8, or 1:9 ratio. When properly cured, these combinations offer concrete blocks with compression strength that exceeds what is typically required in a one-story construction. Concrete block is used instead of mortar to join together horizontal and vertical surfaces, making it easy to use when constructing walls, floors, and other structures.
The best mix for concrete blocks should be able to produce blocks that are light in weight and have adequate compressive strength after curing. The amount of water required depends on the type of sand and gravel used as well as their proportion by volume in the mix. If using coarse aggregates, such as gravel, then more water must be added to obtain workable concrete. If using fine aggregates, such as sand, then less water is needed.
The consistency of the mix can also affect how much water needs to be added. For example, if adding too much water at once, the mixture will not hold together as a solid mass and will just flow out of the container. Also, if adding water past the point where it becomes difficult to stir, the mixture may become lumpy rather than smooth.
The best way to determine how much water to add to your mix is with a test batch. Prepare a sample quantity of the desired mix and pour it into a bowl.