Before you start the pour, ensure that any cavities are free from water, and keep them covered as much as possible. If it started raining before you could cover the slab, don't panic. Simply wait until the rain has passed, then pull or push any surface water off the edge of the slab surface before finishing.
As long as the concrete is given 4 to 8 hours after mixing and finishing to set up, rainwater won't affect it nearly as badly as it could. Some concrete mixes will actually benefit from rainwater on the surface because it's beneficial in aiding the hydration and curing process.
Many people ask whether you can safely pour ready mix concrete in the rain? The answer is yes, it is absolutely possible to pour in the rain, but ideally you should avoid. Rain presents challenges, so doesn't always mean that your schedule is out of the window, as long as you take proper action.
While it is possible, it is generally not advisable since rainwater can affect the strength of the concrete as it cures. Since water is already carefully measured and added into the mix, further addition from the rainwater can be harmful.
It is important to keep in mind that dry-pour concrete may not offer the same level of strength and durability as wet-mix concrete. Dry-pour concrete can also be more prone to cracking and shrinkage, which can lead to structural issues and the need for costly repairs over time.
Concrete that is not moist-cured at all dries too rapidly, and reaches less than half its potential design strength. It will also have a greater number of shrinkage cracks.
Add enough water to make the mix wet enough to ensure good hydration, but not so wet that the concrete mix becomes soupy. If you've over-poured water just add more dry mix and incorporate it until you achieve a good mix.
Pouring concrete into the rain is not advisable, but to pause and wait until the pouring of the concrete is complete. If you are already concreting concrete, remove the surface water before you finish the installation, or wait until it passes and clears the atmosphere.
Long story short, yes you can pour concrete over dirt. However, you need to follow the process outlined in this article for the best results. If this all seems a bit overwhelming, we suggest reaching out to a professional concrete contractor. Razorback Concrete is always willing to work with you.
To protect your new slab and ensure an exceptional finished product you should wait 24 hours for foot traffic (including pets), 10 days to drive light vehicles or add furniture, and 28 days for heavy pick-up trucks and RVs. After 28 days the concrete is cured and you will have a strong and stable slab.
Concrete typically takes 24 to 48 hours to dry enough for you to walk or drive on it. However, concrete drying is a continuous and fluid event, and usually reaches its full effective strength after about 28 days.
If the ambient temperature is too low, the hydration of the cement will drastically slow down or completely stop. Cold weather slows down the setting process or stops it completely, negatively impacting the concrete's strength gain.
You should wait at least 24 hours before walking on your freshly poured concrete. However, make sure not to drag your feet, twist around on it, or let your pets with claws walk on it until later. Bikes, toys, and skateboards should also be kept away from the driveway.
Create a secure formwork that indicates where, and to what depth, the concrete needs to be poured. Form boards will help you outline the appropriate area and keep the viscous concrete properly contained while it sets. Place stakes every few feet along the form boards for additional reinforcement.
Technically you can, but you really shouldn't pour concrete over grass. To maintain its tensile strength, concrete needs to be laid on a firm, even, and dry foundation. Grass and soil will naturally channel moisture into the concrete from below, which will likely result in it cracking over time.
Pouring concrete over existing concrete is possible as long as you do so properly. When the old concrete serves as the foundation for your new pour, it needs to be a solid one.
When the concrete surface is not appropriately hardened, rainfall may wash out cement from its surface and expose aggregates, see Figure-2. This may not affect the structure's safety, but it can lead to uneven surface and color streaking if the concrete is integrally colored.
The Australian Standard 1379: Specification and Supply of Concrete stipulates that concrete temperatures should be between 5°C and 35°C at the point of delivery.
DO spray new concrete with water. One of the most common methods for curing concrete is to hose it down frequently with water—five to 10 times per day, or as often as you can—for the first seven days. Known as “moist curing,” this allows the moisture in the concrete to evaporate slowly.
"Wetness" of concrete as measured by the slump test is directly related to its compressive strength - the 28 day compressive strength of concrete is reduced by about 1.5 MPa for each additional 20mm of slump produced by adding water.
The best way to cure is with continual and consistent watering of the concrete. The concrete must be saturated 5-10 times per day for at least the first 7 days, but ideally 28 days to reach its full effective strength. Sprinkling and ponding are two effective methods for keeping your concrete moist.
Given that concrete foundations are porous, water will fill any pores it can find, eventually causing the foundation to crack and shift, and leaving homes unsettled. If there are cracks present in the walls or ceiling, this may also indicate that water has already reached the foundation.