Curing concrete becomes a more challenging job in colder days. Heavy snowfall and excessive humidity in the air are a few typical sights of the winter season which prevent concrete slabs from hardening properly in time. When temperature goes below 0 degree Celsius or minus 7 degree Celsius, it impacts concrete curing severely.
While undertaking a concrete placement work in colder days of winter, it is recommended that you clean the surface properly and ensure there is no snow, water droplets, dust or any other material present on the surface. Experts recommend use of heat preserving methods for quality concrete pouring during winter days; the heat preserving techniques will help you obtain quality finish.
Concrete curing plays crucial role in building durability and strength into concrete. The process needs specific temperature and moisture conditions to ensure expected final outcome. Properly cured concrete is sturdy enough to stay intact in any harsh weather condition. Let’s continue reading some useful tips on quality concrete curing during colder days.
How different materials can help in quality concrete curing?
You can use different materials based on the total volume of the ready mix concrete that needs to be cured and the size of the surface. Materials like insulating sheets, insulating blankets, straw plastic, windbreaks and heating coils, when used correctly, can help increase temperature as well as help to produce constant heat required for effective concrete hydration process. However when temperature is below minus 7 degree Celsius, it is best to reschedule concrete placement job after while else concrete will not cure properly leading to cracks and poor compressive strength.
Some useful tips for quality concrete curing in cold weather
Following are some proven tips shared by concrete specialists to help you cure concrete properly in winter days.
When temperature is below freezing point, i.e. 0 degree Celsius, make sure the cement to water proportion in the concrete mixture is no more than 0.40. A right water to cement ratio is crucial to perfect concrete hydration.
When it is extreme cold outside, you can use a polyethylene enclosure and a propane heater to prevent quick freezing of concrete mix. Applying constant heat will maintain required temperature for quality concrete curing.
Experts recommend contractors to use Portland cement type III; this particular type of cement lets concrete settle faster without compromising on its quality. Remember, high moisture level can bring on corrosion issues in case of steel reinforcement.
If you remove the insulating blankets abruptly in colder weather, it will create a considerable temperature difference between top and middle layer of the concrete surface. Sudden temperature difference can cause cracks in concrete.
Use of previous concrete is recommended for underwater concrete curing, mainly for flatwork construction applications like pathways. If you aren’t aware, previous concrete is mostly coarse aggregates with a small percentage of fine aggregates, which is mostly sand. Additives are also mixed to prevent water penetration into the surface. Concrete pathways built using this technique will let any large amount of water pass through it but will never allow water get down under the concrete surface, which ultimately help maintain the core strength of the pathway such that it lasts longer.
Be extra careful with the edges and corners. Keep forms intact for maximum feasible time-period.
Use fly ash, furnace slag and silica fume to increase concrete’s resistance to chloride ions. When used properly, fly ash can draw in many benefits to concrete curing. It can help reduce permeability of concrete to water and other fluids. It can also help increase concrete’s resistance value to accede attacks and sulphate attacks.
At lower temperature, concrete curing happens at slower pace. Unlike other days, you will see more bleeding water in a colder day. Keep patience until all bleed water gets evaporated.
The insulation requirement for concrete may vary depending on various parameters like thickness of concrete, minimum air temperature anticipated for the concrete protection period and cement content.
Make use of an infrared temperature gun to verify concrete temperature during curing process. As said above, maintaining right temperature is crucial to quality finish, strength and overall quality of concrete.
You can also use concrete sealants to prevent water getting inside the concrete. Not just it will help avoid failure in curing concrete but will increase the lifespan of concrete.
Hope these tips will help you ensure quality concrete curing for your next construction project.