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If you have ever seen footprints or handprints in dried concrete, you probably guessed correctly that people were allowed to get on the material before it was fully ready. To keep that from happening to you during your next concrete project, here is a guide we put together that informs you on how long it takes before you can walk on concrete.
Timeline for Protecting New Concrete
Drying time, also known as the curing process, is critical in protecting new concrete. And – the greater care you can give to it in the beginning, the longer it stays beautiful and holds up. Of course, once fresh concrete is added to your property, you’ll want to know how long it takes before you can greenlight the area for foot traffic. Here’s a timeline you can follow for when your new concrete will be ready for everyone to walk on.
After a Few Hours
Once the concrete is poured, it begins to dry immediately. Do keep in mind that even though it may appear dry at this stage, it is still wet under the surface and fragile. In fact, you can still mar the concrete after a few hours, so it’s best not to walk on it at this stage. You may see contractors or other workers doing finishing work like adding decorative stamps to the concrete at this point, but it’s smart to leave that kind of work to the professionals.
After 24 Hours
Once the first full day passes, you can walk on the concrete without damaging it. However, X hours is the least amount of time you should wait for the material to harden here in Nashville, TN. If you need to get your patios and driveways open to pedestrian traffic ASAP, talk to experienced Nashville Concrete Contractors Pete and Joe. They’ll be able to discuss with you the processes and concrete mixes that cure material faster without compromising the integrity of the finished product.
Factors That Affect Concrete Setting
Many factors can affect concrete setting time, such as the composition of the cement, admixtures and the water/cementitious ratio. For instance, environmental conditions such as temperature and climate can affect how slowly or quickly cement hardens.
As a specific example, take how warmer weather can cause concrete slabs to dry faster. Adding calcium chloride to the wet mixture before pouring can also hurry the process along, as it is an accelerating compound.
Allow Proper Time to Water Cure Slabs
Concrete performs and looks its best when the water cure slabs are allowed to dry slowly over time. Concrete material which is water cured properly, and for the right amount of time, is approximately 50% stronger than concrete that is not. Therefore, it’s recommended that you keep the concrete covered or wet for the first 7-10 days to slow down the drying process, especially in conditions of direct sunlight. Contractors refer to this process as water curing or moist curing.
The Do’s and Don’ts of Curing Concrete
The procedure of curing concrete the right way requires some finesse and knowledge. The main thing to keep in mind, though, is that you must control the amount and rate of moisture that evaporates from the wet material. Here are some Do’s and Don’ts to follow when curing freshly laid concrete:
DO moisture cure your concrete slab.
The first 7-10 days are essential in the curing process, as it is when concrete increases in structural strength the most. To keep the slab moist and keep it from drying out, you can use the misting technique. Misting involves spraying a fine mist of water at regular intervals across the surface of the slab. The technique maintains moisture levels, keeping the surface damp at all times.
DO cover your concrete slab.
If you don’t have the time to mist your concrete slabs several times a day, you can cover them with a plastic sheet and wet them once a day. While covering the slabs, ensure that the plastic sheet extends beyond the slab’s edges by at least double the slab’s depth. Use heavy items like rocks or bricks will hold the sheet in place and keep it from flapping in the breeze. Every day, remove the sheet and wet the concrete with water. Repeat this process for at least seven days.
DON’T let new concrete get too cold.
The ideal temperature range for pouring new concrete is between 50-60°F. If the temperatures are lower than that, chemical reactions in the material can slow down the curing process and cause damage. Concrete that’s too cold will not gain enough strength – if it gains any strength at all. The fix? Use concrete insulating blankets for the first 2-3 days.
DON’T skip control joints in concrete slabs.
Control joints are necessary for controlling the tensile stress that acts against the weakest parts of the material. If you don’t use them, the result is random cracking of the concrete.
There are different ways to do this, but the most widely used and most aesthetically pleasing way of doing it is to put control joints in the slabs at predetermined locations. The method creates weakened planes where the material cracks in a straight line below the surface of the concrete.
DON’T subject new concrete to excessive weight.
Putting too much weight on your concrete before it’s ready can cause damage. To keep that from happening, here are a few tips to go by during the curing process:
- After a day: Normal foot traffic is typically fine on concrete at this point, but you should still be cautious about damaging the surface by twisting or dragging objects like planters or trash cans across it. Also, prohibit the use of roller skates, skateboards, strollers etc. on your new concrete for the first 24 hours.
- After ten days: For 7-10 days, concrete continues to cure below the surface. After ten days, traffic such as cars, non-industrial machinery, heavy furniture, etc., can resume. However, hold off on the use of bigger vehicles such as trucks and semi-trucks at this stage.
- After 28-30 Days: It typically takes concrete about 28-30 days to fully cure and dry. At this point, it has reached its maximum structural strength. If you’ve taken great care of your concrete up until this point, you can expect it to last for about 50 years. This makes the wait worthwhile, as it results in a good deal of time before you need to replace it.
Let Us Help You get your Feet on Solid Ground
Nashville Concrete Contractors make the concrete construction process easier. From the first contact to contract, we are Nashville’s go-to concrete company; specializing in driveway and patio installation and repair, as well as decorative and stamped concrete design. Contact the NCC team today at 615-505-3595 to have our experienced concrete division assist you with your next concrete-related project.