Concrete is one of the toughest and most durable construction materials known to man. In fact, it was the invention of steel-reinforced concrete that led to the massive bridges and skyscrapers we take for granted today.
Using a concrete mix (like Quikrete) in a project around the house can be a fun and rewarding experience. However, it’s not the most forgiving of materials to work with. You’ll need to plan for mixing and pouring while keeping in mind concrete has a limited time to work with before it hardens.
Whether you’re putting in concrete footings for fenceposts, pouring a slab for a driveway, or putting in concrete stairs, you’ll need the answer to “how long does it take Quikrete to dry?”
Concrete Drying Explained
Concrete is a composite material made of aggregate (sand and rock) and a binder (cement). When water is added to the mix, the binder is activated and the mixture turns into a semi-liquid sludge. At this point the figurative timer has started on the concrete drying, so you’ll have a limited time to mix, pour, and shape it.
The hardening process occurs when the water reacts with the cement, which begins to bind the other materials together.
Different concrete mixes are designed to dry and cure at different rates. Fast setting concrete products, like Quikrete’s Fast Setting Mix, will dry in approximately 20 to 40 minutes and will cure enough to bear weight after 4 hours.
The typical ready-mix concrete mix takes significantly longer to dry. It will remain semi-liquid and workable for about an hour and will dry to approximately 50% of its strength in 24 hours. At this point, it usually ready for people to walk on. After 48 to 72 hours, it’s normally ready for small vehicle traffic, and after 14 to 30 days it will harden to its full strength.
Factors Influencing Concrete Dry Times
In addition to the particulars of the concrete mix, there are a number of other factors that influence how long Quikrete takes to dry.
Temperature is a major factor to consider when mixing and pouring concrete. The hotter it is outside, the faster your concrete will dry. Alternatively, the colder it is out there, the longer the drying process will take.
Varying temperatures can have a major effect on the final product. High levels of heat not only cause faster drying but can also cause the concrete to dehydrate, which leads to a weaker final product.
Because of this, in the hotter summer months, mixing and pouring concrete early in the morning or late in the afternoon makes sense. This will ensure the chemical reaction takes place at the right temp, and the concrete has dried significantly by the time the mid-day sun hits.Other precautions you can take in high temperatures are storing the dry mix in the shade until it’s ready to use, using cold water to mix, and damping the sand or gravel you’re pouring the concrete onto. Once the concrete is poured and leveled, a sprinkler or fine mist hose can help keep the temp down.
On the flip side, using concrete in cold weather comes with its own set of challenges. While mild cold temperatures slow down the drying and curing process – resulting in a stronger final product – freezing temperatures can make pouring much more difficult.
If the concrete is allowed to freeze as its drying, it will lose up to half of its final strength. To prevent this from happening during the drying process, you can use hot water for mixing, add a chemical accelerator to the mixture, and use concrete blankets to warm the ground before and after pouring.
As the concrete cures, you’ll want to make sure it stays as warm as possible. Covering the concrete with blankets, burlap cloth, or concrete blankets will trap in heat and keep it warm as it cures.
In order to avoid the above complications, it’s best to pour concrete during moderate (60° to 80° F) temperatures.
The water/cement ratio is another major factor influencing concrete drying times. Different manufacturers will recommend different amounts of water to add to the dry mix – and it’s best to stay within these recommendations.
Quikrete’s standard mix recommends a range of 1.9 to 3.3 liters of final water content per 60 lbs. bag. The higher water content will create a looser mix, which will also take longer to dry.
You might be tempted to use less water than recommended to speed up dry times – don’t. This will only result in a weakened final product, as less water means fewer chemical bonds between the components.
Concrete Mix Type
As mentioned previously, the specific type of concrete mix will impact drying and curing times. If you need a fast-drying concrete, there are quick-dry products designed to dry rapidly and cure enough to bear weight in just 4 hours. These are useful when you’re installing fence posts, mailboxes, deck posts, and other posts.Quikrete also makes a quick-setting cement product that’s specially designed to set in just 10 minutes. This rapid drying time makes it ideal for small repairs and cast projects.
Standard mix concrete dries enough to walk on in about 24 hours, and increases in durability to about 70% of its final strength in 7 days. Make sure to read the fine detail on the back of the concrete bag before applying any serious weight.
The important thing to keep in mind here is matching the concrete product to the task at hand. Also, you never want to mix different types together – as the final product will be unpredictable.
How long does it take concrete to cure?
Yes, there is a difference between concrete drying and curing.
Generally, drying refers to the time it takes for the concrete to ‘set’, which means turn from a paste into a solid. Once it’s set, it can handle light foot traffic, but it’s still a long way from reaching its full strength.
The curing process refers to keeping the concrete in ideal conditions for it to reach its final strength. The total time until the concrete is completely cured is typically about 30 days.
However, it doesn’t cure on a linear scale. The first 3 to 7 days is when the majority of the curing process takes place, and after 7 days it’s typically cured enough for vehicles to drive over. From 7 days out to 30 days, the final 10% of the curing process takes place, bringing it to its final strength.
Hopefully, you now have a good answer to “how long does Quikrete take to dry?“. Whatever concrete project you have planned, knowing how long your Quikrete will take to dry will save you from serious headaches, and help everything go smoothly.