When dry, standard reinforced concrete weighs 150 pounds per cubic foot, although there are "light" varieties that can weigh as little as 100 pounds per cubic foot or as much as 300 pounds per cubic foot. As it cures, the weight of the concrete increases as water is driven out of the material.
Concrete does not get "harder"; rather, its strength increases. Concrete's strength depends on two factors: the type of cement used and the amount of water added during mixing. As water is removed through drying, the concrete will continue to harden but will become less flexible. This is called "curing" or "drying" depending on the temperature of the environment. At normal temperatures, concrete dries over time but if left exposed to heat or sunlight, it will quickly cure. Curing also can be sped up by adding moisture, such as rain or dew.
As a concrete slab dries, it will also shrink slightly due to loss of water. This is called "desiccation" and it occurs primarily in warmer climates. If desiccated too much, it may cause cracks to form in the slab. To prevent this, the concrete industry has developed several products that can be used to maintain some level of hydration while still allowing the slab to dry out.
Say it out loud: Pause Concrete weighs around 150 pounds per cubic foot, or 4,050 pounds per cubic yard. That's about the weight of a small car! A cubic yard is about 1/3 ton. There are 8 feet in a meter so 1 m of 3-inch-thick concrete will weigh about 50 kg. Or 110 lb.
Concrete doesn't just fall out of the sky; trucks bring it to the site and dump it. The more you can tell us about the project, the better we can help you find the right materials and get the job done cost-effectively. So answer these questions and others in our Concrete Questions & Answers section.
The overall weight of a cubic yard of concrete depends on how much water it contains. If the concrete was mixed properly with high-quality ingredients and finished with fine aggregate, then it should be very light to touch. Heavy concrete may indicate that poor quality materials were used or that the mix was not stirred adequately.
Heavy concrete may also indicate that excess air was included in the mixture, which tends to make the concrete dry out as it cures.
How Much Weight Does Concrete Have? A standard concrete mix weights 150 pounds per cubic foot, 4,050 pounds per cubic yard, or 2,400 kilograms per cubic meter. Concrete's weight is determined by its density, which varies depending on the amount of aggregate, water, and air in the mix. The average weight of a cubic foot of concrete is 810 grams (or 27 ounces). A cubic yard weighs about 2,000 pounds or 914 kg. An average-size concrete slab, 5 feet by 8 feet, would weigh about 500 pounds or 230 kg.
Concrete's weight can also be measured in tons per square foot. One ton is defined as 1 kilogram times mass of Earth's surface. If we assume that the mean density of concrete is 1300 kg/m3, then one square foot of concrete weighs 0.9 kg or 2.2 lbs.
The typical strength of concrete allows for loads to be applied in three different ways: compression, tension, and shear. As long as those forces are equal, the concrete will not fail. Too much force in one direction may cause the cement paste to split open, but this is not common with normal concrete mixes.
When concrete is placed in forms it is under pressure, so the weight of the concrete will compress the forms. The amount of compression depends on the size of the form relative to the size of the piece being cast, as well as the type of form used.
Density can also be affected by other factors such as temperature and type of cement used.
Concrete's mass is made up of two parts: solid material and air voids within the mixture. The average volume of concrete that a person can lift is about 0.5 kilogram. A cubic meter of concrete weighs 10 tonnes.
The specific gravity of dry concrete ranges from 1.6 to 1.9. The average is 1.7, so it's slightly heavier than water. Concrete's weight increases as it cures because of the drying effect of oxygen inside the mixture. When it's fresh, concrete weighs less than water because there's more surface area exposed to air. As time passes, the oxygen in the concrete reacts with moisture in the soil or structure beneath it, causing the concrete to harden and gain weight.