How to Pour Concrete in Hot Weather: Tips for Success with a Volumetric Mixer

The Summer Concrete Challenge

Pouring concrete in the summer heat isn’t just uncomfortable—it can be a serious quality control problem. If you’re working in the blazing sun and high humidity of July or August, you know the stress that comes with trying to beat the clock before your concrete sets too fast or cracks prematurely. But what if you could control the temperature, timing, and mix composition on site?

Enter the volumetric concrete mixer—a game-changer for hot weather pours.

This blog explores the real challenges of pouring in hot weather, and how volumetric mixers allow contractors to not only adapt, but thrive in summer conditions.

Why Hot Weather Complicates Concrete Work

Before diving into solutions, it’s important to understand how summer heat impacts concrete.

1. Accelerated Set Times

As temperature rises, chemical reactions within concrete (namely hydration) occur faster. At 30°C (86°F), concrete can begin setting in under an hour—half the time it takes at 20°C (68°F).

2. Increased Water Demand

Hot weather means faster evaporation. To maintain workability, many crews add water, which weakens the final mix and increases the risk of shrinkage and cracking.

3. Thermal Cracking

When surface temperature changes too quickly—like cooling at night after a 35°C day—it can cause differential stress within the slab, leading to cracks.

4. Plastic Shrinkage Cracking

Rapid water loss before curing can lead to shrinkage cracks forming on the surface before the concrete has hardened.

5. Hot Loads and Wasted Batches

With drum trucks, long delivery times or delays on-site can result in unusable concrete arriving at the jobsite.

How Volumetric Mixers Solve Hot Weather Problems

Volumetric mixers provide the flexibility, control, and real-time adjustments that summer demands. Here’s how:

1. On-Demand Mixing

Since materials are stored separately and only mixed on-site, there’s no such thing as a “hot load.” You mix exactly what you need, when you need it—no stress, no waste.

2. Real-Time Water Control

Volumetric mixers let you control the water content on the fly. You can fine-tune the water-cement ratio to account for current conditions without compromising strength or mix design.

3. Admixture Control

Most volumetric mixers allow for liquid admixture systems. In hot weather, retarders are key—they slow down setting time to give you longer workability and reduce the risk of cracks.

4. Batch-by-Batch Adjustability

If the temperature rises during your pour, you can immediately adjust the next batch’s mix proportions. That’s impossible with traditional drum delivery.

5. Jobsite Efficiency

Crews don’t have to rush. With fresh concrete available continuously, you can place and finish with confidence—even in high heat.

ProAll Commander 2.0: Heat-Ready Technology

The Commander 2.0 system, available on ProAll volumetric mixers, provides a fully automated control panel that gives you unprecedented command over every aspect of your mix. On hot days, you can:

• Increase or decrease water flow precisely

• Track mix temperature with integrated sensors

• Adjust mix design on-site

• Use pre-programmed recipes with built-in retarder levels

The result? Concrete that’s tailor-made for July in Texas, Arizona, California—or anywhere the heat is on.

Tips for Pouring Concrete in Hot Weather Using a Volumetric Mixer

Here’s your summer heat survival guide.

1. Plan Your Pour Times

Schedule pours during cooler parts of the day:

• Early morning (6am–10am)

• Late afternoon or evening (after 6pm)

Avoid 11am–4pm when the sun is most intense.

2. Use Set Retarders

Retarding admixtures slow hydration and extend workable time. Most volumetric mixers can carry liquid admixtures onboard. Set retarders give you more control and peace of mind.

3. Keep Materials Cool

If possible, shade your aggregate bins or spray aggregates with cool water ahead of the pour. For high-volume pours, try storing materials in shaded areas or using light-colored covers.

4. Control Water Content

Don’t just dump extra water into the mix to fight slump loss. Instead:

• Use water-reducing agents

• Adjust the water dosing via the control panel

• Monitor and maintain your designed water-cement ratio

5. Speed Up Curing

Start the curing process immediately after finishing:

• Spray-on curing compounds

• Evaporation reducers

• Wet burlap or polyethylene sheeting

This helps retain moisture in the slab and reduce surface cracking.

6. Use Wind Breaks and Sunshades

On extremely windy or sunny days, use temporary shade structures or wind barriers around your pour area to prevent rapid surface drying.

Real-World Example: Pouring in the Desert Heat

A concrete contractor in Phoenix, Arizona uses a ProAll P85 with Commander 2.0 to supply curbs and sidewalks throughout Maricopa County. In 2024, they completed over 2,000 cubic meters of concrete during August—without a single rejected load.

Their process:

• Early morning pours before 9am

• Onboard retarders adjusted by temperature

• Real-time mix adjustments via Commander 2.0

• Crew cooldown breaks every 30 minutes

By using a volumetric mixer, they eliminated hot load concerns, improved quality, and reduced waste.

Hot Weather Concrete Checklist (Free Download Available)

Before the Pour

• Confirm temperature forecast

• Load retarder admixture

• Check water tank levels

• Shade aggregate bins if possible

During the Pour

• Monitor mix temperature

• Adjust water/admixture as needed

• Use sunshades or misting near pour area

• Begin curing immediately after finishing

After the Pour

• Maintain moist curing conditions

• Avoid traffic until proper strength is reached

What Happens If You Ignore the Heat?

Hot weather isn’t just inconvenient—it can be costly.

• Rejected pours due to slump loss or premature set

• Strength loss due to improper hydration

• Increased cracking from plastic shrinkage

• Wasted labor waiting on replacement batches

• Lost reputation if clients see subpar finish quality

Volumetric mixers don’t just help you survive the heat—they help you thrive through it, offering unmatched control and peace of mind.

Volumetric Mixers vs Drum Trucks in Summer: A Quick Comparison

Training Your Crew for Hot Weather Success

Even with the right equipment, your crew needs to be prepped for heat. Some tips:

• Hold pre-pour meetings in the shade

• Provide electrolyte-rich water on-site

• Assign one person to monitor mix consistency and make changes as needed

• Rotate finishing crews to avoid heat exhaustion

ProAll offers customer training programs and how-to videos to help your team get the most out of the Commander 2.0 system—even in extreme weather.

The Long-Term ROI of Hot Weather Flexibility

If you pour year-round, especially in warmer climates, having a volumetric mixer in your fleet pays off fast:

• Fewer rejected batches

• Lower labor costs from fewer delays

• Higher-quality end product

• More jobs completed on schedule

• Improved customer satisfaction

Contractors who make the switch to volumetrics often wonder how they ever managed without it.

Stay Cool, Stay in Control

Concrete doesn’t stop for summer—and neither should your business. Volumetric mixers give you the ability to pour with precision, confidence, and flexibility in the most challenging hot-weather conditions.

No more guessing.
No more wasted loads.
No more heat-induced chaos.

Just better concrete, poured when and where you need it.

Get Started with ProAll Today

Whether you’re dealing with 35°C (95°F) temperatures or unpredictable summer storms, ProAll’s line of volumetric mixers—especially those equipped with the Commander 2.0 system—can help you maintain quality, stay on schedule, and keep your crew cool.

👉 Contact us to learn more about how a ProAll mixer can transform your hot-weather pours.
👉 Explore our full lineup of volumetric mixers for every type of job.
👉 Book a live demo and see how Commander 2.0 gives you real-time control.