Tips for Pouring Concrete in Winter

When it comes to pouring concrete in winter, weather can pose significant challenges. Concrete sets best at 50-60°F; pouring concrete in winter means the ambient temperature will likely fall well below this range. Fortunately, there are steps you can take to effectively tackle cold weather concrete curing.

Concrete Pouring Temperature Limits

As mentioned above, concrete prefers a mild temperature between around 50 and 60°F to set. Below this, the exothermic reactions that cause wet cement to transform into strong concrete will slow significantly. This could mean long delays in work while you wait for concrete to set and strengthen before continuing with a project. Additionally, If concrete reaches freezing temperatures during the setting process, the water in the cement mix will freeze and expand. This will cause concrete to become weak, brittle and even flaky when it sets.

 

Successfully Pouring Concrete in Winter

Fortunately, strategies can be implemented to increase the temperature of cement mixtures. Here are some tricks you can use to keep the cement flowing all winter long:

  • Use heaters or heated blankets to thaw surfaces where concrete will be poured. Pouring concrete on frozen ground will quickly cool concrete well below ideal temperatures. Using a heater to prep surfaces will prevent too-quick cooling or freezing and help keep the necessary reactions going.
  • Mix cement using hot water to help increase the temperature of the concrete.
  • Store materials in a warm location.
  • Use quick-set cement; during cold weather. It may set more slowly than the instructions indicate, but will still harden more quickly than traditional cement mix.
  • Mix in additives that accelerate set time.
  • Use extra cement (typically 100 lb/ cubic yard) to make the reaction hotter and cause concrete to hydrate more rapidly.
  • Utilize squeegees or a vacuum to remove bleed water that has a difficult time evaporating during colder weather.

Cold Weather Concrete Curing

After the concrete has been poured, it needs to be kept at the correct temperature to cure. Most importantly, it needs to be kept from freezing. Ideal temperatures (50-60°F) should be maintained for about 48 hours for the concrete to reach optimal strength as it sets. This can be tricky during the winter; even if temperatures are optimal during the day, they can plummet at nighttime. Maintaining warmer temperature will require some sort of external heat source. One option is a heated enclosure. These are effective but can be time-consuming to install. If you choose to use an enclosure, be aware that excess carbon dioxide from the heater can cause bubbling in the surface of concrete. This can typically be avoided with proper ventilation.

Concrete Blankets

Another option for temperature maintenance during cold weather concrete setting is concrete blankets. Concrete blankets can be used to thaw ground before pouring concrete and again after finishing to keep concrete from freezing. They are easy to install and transport and require only an outlet to use. This means no time wasted setting up complex heating mechanisms. If you’re interested in minimizing downtime involved pouring concrete in winter, these blankets are an excellent heating option to look into.

The Effects of Pouring Concrete in Cold Weather

Effects of Pouring Concrete in Cold WeatherEffects of Pouring Concrete in Cold Weather

First, let’s define cold weather with respect to pouring concrete. Any time you have three consecutive days where the average daily temperature is less than 40°F, or if the temperature is lower than 50°F for less than half of any of the three days–that is unpleasantly cold for concrete. Pouring concrete in cold weather will have a detrimental affect on concrete curing for several reasons.

How Does Concrete Cure?

Concrete transforms from a liquid to a solid material through a chemical reaction. The speed of the reaction depends upon the temperature of the concrete. When the weather is warm, the reaction proceeds quickly. When it’s cold and the ground hasn’t been thawed, the reaction slows down. That’s the problem: the concrete needs to harden as rapidly as possible to resist pressures caused by water freezing within the concrete.

Slower Chemical Reactions

If the temperature is too cold, the concrete may not have reached a minimum strength of 500 psi soon enough to resist the effects of freezing temperatures. If your concrete isn’t protected with concrete curing blankets after it’s poured, it may cool too rapidly, slowing the chemical reaction.

Poor finishing techniques can also doom your slabs. Freshly poured concrete often bleeds. The water in the mix floats to the top, since it’s the lightest ingredient. Floating or troweling this water into the concrete weakens the top layer. Troweling the concrete too early can seal this bleed water just below the surface as well. If your slab is then exposed to freezing temperatures several days later, this water can freeze and fracture the top layer. Using a concrete curing blanket can eliminate the potential of freezing.

Read how Powerblanket solved concrete issues at the Statue of Liberty.

 

Concrete Can Be Successfully Poured in Cold WeatherThe Effects of Pouring Concrete in Cold Weather

How to avoid a bad concrete pour:

  • Never pour concrete on frozen ground, snow, or ice. 
  • Be sure to order air-entrained concrete. Request a heated mix or order 100 lbs of extra cement for each cubic yard of concrete. This extra cement helps develop early strength.
  • Be sure the concrete is ordered with a low slump (drier mix). This minimizes bleed water.
  • After the final finish is completed, cover the concrete with a concrete curing blanket. The heated concrete blanket will prevent freezing and keep the concrete at an optimal curing temperature.
  • After about three days, remove heated concrete blankets to allow the concrete to air dry.

Powerblanket Concrete Curing Blankets

If you use Powerblanket Concrete Curing Blankets to pour in cold weather, your cement will cure 2.8 times faster than with conventional insulated blankets. Time and convenience are critical factors when planning out a project in the winter, and Powerblanket has you covered.  Our goal is to provide solutions to problems, and give you total temperature control over every process and aspect of your business.

We Solve Problems

From drum and barrel heaters to pipe wraps and snow melting mats, Powerblanket is dedicated to helping your business grow, saving jobs, and improving your bottom line.   Whether you need to extend the pouring season, or you are trying to survive an early winter, know that you have total temperature control with Powerblanket.

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Powerblanket® | The Ultimate Concrete Curing Blanket – The ONLY Concrete Curing Blanket!

Concrete Blankets From Powerblanket®

Cement Curing Blankets

Cement curing has always been a challenge in cold weather. Historically, experts have employed many different methods in order to aid in and speed up the curing process. Some methods are better than others. The best, in our opinion, is using concrete curing blankets from Powerblanket. Here’s why:

Concrete Curing Blankets

 

Why Electric Curing Blankets?

When placing concrete in cold weather, protecting the asset (the concrete) is not optional. For years now, experts have used insulated blankets to both protect the concrete and speed the curing process at the same time. Concrete cures due to a chemical reaction that generates heat as a byproduct. So insulating the concrete allows that heat to be trapped and used to aid in the curing process. Concrete cures fastest in very warm conditions, so this makes the use of an insulated blanket a practical and theoretically sound practice.

Of course, the use of traditional concrete curing blankets isn’t the only method employed among professionals. Other common curing interventions include:

  • Chemical additives
  • Hydronic heating systems
  • Electrically-powered concrete curing blankets
  • Poly/tarp cover with forced air heat applied

Sometimes the circumstance will allow for the luxury of a postponed pour, in order to take advantage of an expected temperature change.  But more often than not, schedules and deadlines make it imperative to institute curing assistance to get through less-than-favorable weather.

This is where Powerblanket Concrete Curing Blankets come in. As much as traditional curing blankets aid in protecting and accelerating the curing process, Powerblanket curing blankets provide both insulation and heat, protecting and accelerating all the more. Our patented blend of technology delivers an even distribution of electrical heat to the surface area of the blanket, trapping the heat of the chemical reaction in the concrete and adding the additional heat needed to accelerate the process even further.

Since Powerblanket Cement Curing Blankets insulate and heat, they effectively accommodate the hydration of the concrete as well. How well do they really work? Take a look at our case study to see an example of curing nearly three times as fast with our blankets.

The technology behind Powerblanket curing blankets serves to achieve several primary objectives, including:

  1. Preventing damage as a result of freezing in the early stage of curing
  2. Producing sufficient, specified strengths in a timely manner
  3. Insuring durability and long-term structural integrity
  4. Keeping projects on schedule, regardless of weather

So before you’re faced with a project that must go on despite inclement temperatures, make sure you have a plan on how to protect your concrete and keep your deadlines met. When considering the options you have before you, we’re confident you’ll find our solution to be the best answer out there.

 

Read the Case Study for Evidence that Powerblanket Cement Curing Blankets:

  • Cured concrete 2.8 times faster than conventional insulated blankets
  • Cured concrete 1.7 times faster without adding additional heat (un-powered)
  • Produced cold weather concreting strength of 3,925 psi in 72 hours

 

Additional Features:

  • Maintain moisture throughout hydrating process
  • Maintain ACI compliance for cold-weather concreting

 

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Precast Concrete and Throughput: How to Improve Cure Times

The business of precast concrete manufacturing is one where you often have to hurry up and wait. Once you pour a precast form, you then have to wait for the time-consuming process of allowing the form to fully cure. The importance of proper curing can’t be undermined, but what if it could be efficiently and safely sped up?

 

Precast Concrete InfographicCure Precast Concrete 3 Times as Fast

What if we told you that you could speed up your precast concrete curing process, without the use of any additives, by as much as 300%? If you’re first thought is: prove it, then we would love to. In fact, it may interest you to know that the inception of Powerblanket heating solutions all started with concrete curing in the first place. We’ve been in the business of increasing concrete-curing efficiency for many years, and our solutions have been proven and tested innumerable times over to increase curing efficiency without any of the common side effects related to other forms of acceleration.

Additives can dehydrate your concrete and leave you playing a game of gains and losses. But Powerblanket custom precast concrete curing solutions keep your concrete insulated and hydrated throughout the curing process. Our patented blend of technology allows for the even and consistent curing of precast forms of all shapes and sizes.

So rather than balancing the pros and cons of using additives or accelerators in your concrete forms, let us show you a solution that creates no setbacks, only progress. To learn more about our precast curing blankets, select the button below for the infographic.

 

Precast Infographic

 

Powerblanket Receives Manufacturer of the Year Award from UMA

If you haven’t seen this headline somewhere else on the web by now, we’re happy to tell you all about it here. Utah Manufacturers Association recently awarded Powerblanket something we’re pretty happy about. Read on to learn more about the UMA Manufacturer of the Year Award.

 

UMA AwardUMA and Manufacturer of the Year

Utah Manufacturers Association (UMA), recently awarded Powerblanket the prestigious award  of Manufacturer of the Year. This award is given annually to the Utah-based manufacturer that proves to be the most innovative contributor to their space. There’s even more to it than this, but we’ll get to that.

UMA has been around since 1905. The organization prides itself on offering the “voice of industry” in the state of Utah, and they’ve been doing so for over 107 years now. UMA has clearly been talking Utah economy for a long time, but talking isn’t all they do. UMA is a trade association, and their goal is to enhance and improve the business climate in the state. UMA doesn’t only offer insight and expertise in the business of manufacturing, but the organization also has considerable experience in the legislative processes of state government. This is how they can do so much to vie for the interests of Utah businesses and the overall economic prosperity of the state.

UMA’s Manufacturer of the Year Award embodies the mission of UMA in multiple ways. By awarding the company that not only proves innovative in their respective markets, but also offers leadership in their industry, UMA’s award encourages and rewards the same idealism by which their organization operates. Powerblanket was chosen to receive this award for 2015, based on the embodiment of these characteristics and more. In fact, why don’t we just give it to you in their own words. According to UMA, Powerblanket received the award “for their outstanding performance in operational excellence, economic achievement, workplace safety, community outreach, and fidelity to the principles of free enterprise.”

Powerblanket is honored to receive such accolades from a high quality establishment like UMA. The credibility of UMA and the Manufacturer of the Year Award lends a great addition to our own image and ethos as a company devoted to “operational excellence, economic achievement, workplace safety, community outreach, and fidelity to the principles of free enterprise.”

So, from all of us here at Powerblanket, thank you, UMA for this great privilege.

 


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Concrete Curing: Not Just a Wintertime Problem

If you’re in the business of concrete, then you know that winter poses the most complications when it comes to proper concrete curing. However, you’ll be equally aware of the fact that summertime also has its challenges.

 

Concrete Curing- Not Just a Wintertime Problem

Summertime Concreting

Sure, winter is a far more difficult time to deal with when pouring concrete. Proper curing involves ideal temperatures, and winter imposes on these ranges more than any other season. That’s why when it comes to pouring concrete in winter, you need the assistance of a good concrete curing blanket. But what can be done to counter the challenges of summer, and what are those primary challenges?

In the summer months, you don’t have to worry about freezing temperatures. Instead, you need to watch for levels of relative humidity, temperature fluctuations between night and day hours, and an increase in the water demand for concrete curing. With these factors to consider, careful monitoring of the concrete is still an important element of the job. Hotter temperature and low humidity can increase the need for additional water, and large fluctuations between the daytime and evening temperature can pose significant problems too.

If there is the risk of a rapid drop in temperature, then there is the risk that your concrete could crack. Even though the temperature may be ideal for curing during the day, that doesn’t mean it will be at night. Certain regions can experience significant temperature variances between daytime and evening hours, and these variances should be considered potentially problematic while your concrete cures.

 

Using a Concrete Curing Blanket in the Summer?

It may seem a bit of a stretch to suggest the use of a curing blanket during the summer months, but the reality of the situation is that it can be a very reasonable call. Think about the potential scenario of dropping temperatures at night. If your concrete is curing well during the heat of the day, and then experiences a drastic drop in temperature at night, then it’s going to affect the cure and even cause potential cracking.

Using a concrete curing blanket at night would allow you to regulate the temperature range even if it’s dropping. This would produce a more uniform cure and would also speed up the process significantly. The blanket likely wouldn’t be needed during the day, but applying it at night could greatly decrease the fail rate of an expensive and time consuming project.

 

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Powerblanket at the World of Concrete—A Demo in Concrete Curing

Earlier this month, Powerblanket attended the 2015 edition of the World of Concrete at the Las Vegas Convention Center. This year’s exhibition attracted 55,779 registered professionals. In addition, the event drew in 1,459 companies exhibiting their products and services. For Powerblanket and its concrete curing demo, the event proved to be a great way to engage with those in need of the company’s products.

 

Powerblanket at the World of Concrete—A Demo in Concrete Curing

Powerblanket and the World of Concrete

For Powerblanket, this year’s World of Concrete was an exciting investment of company time and resources. Powerblanket ran a concrete curing demo to demonstrate the effectiveness of Powerblanket® curing blankets on the set times and structural integrity of concrete pours. Those who were present were able to witness for themselves how much efficiency the curing blankets added to the curing process. Not only were the blankets able to cure the concrete nearly three times as fast, but they were also able to increase the strength of the concrete by 50%.

The slab used for the demonstration was 8” thick with a mix design that was formulated to provide a minimal PSI of 4,000 in only two days.  The slab was poured two days prior to the demonstration, and for the purposes of the demonstration, one portion remained unheated while the other section was covered in an MD series Powerblanket® curing blanket. At the beginning of the demonstration, the unheated portion of the concrete measured close to the 4,000 PSI that was required for the minimal target. Then the Powerblanket was added, and the portion of the slab that was heated by the Powerblanket MD Series concrete curing blanket measured a consistent 6,000 PSI after only 16 hours in place. That’s a PSI strength increase of 50% over the unheated portion of the concrete slab.

Powerblanket® curing blankets allow for such efficiency through the company’s patented technological approach to concrete curing and many other heating solutions. Not only do Powerblanket® curing blankets insulate the chemical reactions responsible for concrete heat exchange, but they also add heat to the equation—making them far more efficient than the common curing blanket.  Through the Powerblanket design, electrical heat is evenly distributed through the entire application, allowing for quicker set times and stronger concrete.

“Seeing people’s reactions to the demonstration was exciting,” said Ryan Jensen, Marketing Director for Powerblanket. “It was clear that everyone was impressed with the outcome.”

As a result, Powerblanket has engaged with more customers in an industry they already heavily serve.

 

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The Cure for the Common Cold Concrete

If you’ve ever had to lay concrete in the cold, then you can attest to the fact that it doesn’t set up as fast as it aught too. Actually, inclement weather can delay the curing of concrete considerably.

 

Heating Mortar Ingredients for Cold Concrete Weather Masonry

The Cure

When it comes to curing concrete, the optimal temperature is easy to obtain most of the time…if it’s summer. But what about all the other months of the year? What do you do when winter rolls around? More often than not, winter will put a screeching halt on the progress of temperature-sensitive construction projects, and concrete is one such example.

When concrete is subjected to cold weather, the time is takes to adequately cure increases significantly. According to the Portland Cement Association (PCA), “compression strength of concrete cured at 50 degrees Fahrenheit is expected is expected to gain strength half as quickly as concrete cured at 73 degrees Fahrenheit,” (PCA). So how do you speed up the process?

 

Insulation or Heat Application

A long standing-tradition for protecting concrete against the cold is to apply insulation to the concrete after it is hard enough to maintain its form under the weight of an insulation blanket. While this helps to keep the concrete from dropping in temperature drastically, it does nothing to bring the cement to an ideal temperature. However, there is an option that does this very thing.

Along with insulation blankets, there are concrete curing blankets.Concrete curing blankets not only help to insulate concrete against the cold, but they also help to raise its temperature and that of the ambient air around it. Done right, concrete curing blankets can be dialed in to a certain temperature and left to do the job without monitoring.

 

PCA

http://www.cement.org/for-concrete-books-learning/concrete-technology/concrete-construction/curing-in-construction   

See all the details of the Powerblanket® concrete curing blanket by downloading the free product spec sheet!

 

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