How to make lightweight concrete. Concrete is created using a special blend of cement, sand, and gravel which act as the key ingredients in its composition.
Concrete has been used throughout history for its sturdiness and strength, particularly within architecture. In order to lighten the overall weight or to cut back on expenses, contractors may make use of lightweight concrete for their projects.
One can achieve this result by increasing the proportion of sand – instead of gravel within your concrete mixture to produce a lighter version of traditional concrete mixtures.
How to make lightweight concrete
When using less sand while building with concrete, one can make the product lighter, but this tradeoff is that making it less dense also makes it weaker structurally.
A simple recipe for basic lightweight concrete is to combine 8 parts sand, 8 parts cement, and 5 parts water with the addition of 5 parts perlite essentially a bigger mesh particle that can absorb more water in your mix.
Combining lightweight concrete
There are different recipes to make concrete depending on what aggregate is used. With fine aggregates, you can use as much as 70% less cement without losing strength.
There are variations in the amount of water needed: if your sand is from a fresh source, you’ll need less water than if it had already dried out.
For basic lightweight concrete, mix 8 parts sand, 8 parts cement, and 8 parts perlite; then pour this into 5 parts water.
This works as long as no large stones (core material or any weirder shapes) are mixed, in this case, using lightweight aggregates doesn’t help because their density is higher than that of concrete.
There are many recipes available for concrete. We’ve created a tailored recipe that is best suited for this project. In general, it is important to wear a mask to keep dust out of one’s lungs and gloves to avoid burns from the heat.
Also, add the water slowly as the humidity can affect how much water needs to be added. It will depend on what you’re using to mix the concrete too because some items may need more or less water than others.
When in doubt, go with more water instead of less because you can always take it out, but adding water later will be impossible.
Lightweight concrete contains aggregate materials that are much lighter than traditional concrete. For example, while an average square foot of lightweight concrete weighs 14.5 pounds, traditional concrete weighs around 18 pounds.
This can be a big difference in weight when it comes to things like planters that you want to move around easily but lightweight concrete may prove too heavy for some jobs.
If you want to use lightweight concrete but don’t want to prepare the mixture yourself, there are pre-mixture options for sale at your local home improvement store that require only water and can be very convenient for those looking to make small projects.
It’s impractical to buy whole bags of sand, cement, and lightweight aggregates individually so these mixes are great ways to cut down on time.
Benefits and Disadvantages
In contrast to normal concrete, lightweight concrete is not as strong. This material is suitable for use in planters and structures that need insulation rather than strength.
The main drawback is the fact that lightweight concrete does not support weight well, so it should be used only on top of wooden or steel beams rather than on load-bearing supporting walls.
Under most circumstances, though, lightweight concrete should be permitted in place of traditional concrete as long as it has a larger surface area with air pockets that do not touch each other within the same layer.