While it’s too early to say if the summer of 2022 is one of the hottest on record, the heat has been record-setting across the U.S. and the end of summer promises little relief. Handling busy summer schedules in the midst of heatwaves isn’t unusual in the pavement business, but it’s still good to remember these important tips to keep your crews and your pavement cool the rest of the season.
Pouring concrete is best when temperatures are between 50℉ and 70℉ but it’s unrealistic to wait until the perfect day to begin a job. When you place concrete in temperatures above 75℉, controlling the rate of evaporation becomes the main concern. Here are some tips to prevent cracking due to rapid evaporation in high temperatures.
- Use the Right Mix
The use of chemical admixtures like fly ash and low heat cement mixes help maintain strength and extend the mix’s working time in hot weather.
- Choose The Best Time
To minimize the effect of high temperatures, schedule concrete work to be done early in the day or in the evening if possible.
- Have A Full Crew And Equipment Ready
Since concrete sets faster as temperature rises, make sure you have enough crew on hand to do the job and all equipment is ready prior to pouring concrete.
- Use Evaporation Retarders
These monomolecular films are applied after concrete is poured to reduce evaporation from wind and sun in high temperatures.
- Use Sunshades and Windbreaks
This is a simple but effective way to keep concrete cool and maintain moisture.
For a complete guide on how to pour concrete in high temperatures, read the American Concrete Institute’s Guide to Hot Weather Concreting.
Asphalt can be laid with temperatures up to 90°F. Once the temperature climbs above that threshold, it takes longer for asphalt to cool. Keep these tips in mind when handling asphalt on those hottest summer days.
- Schedule Carefully
Avoid asphalt jobs on days that are typically above 90°F for your area.
- Monitor The Temperature of Your Mix
Be aware of the temperature of the asphalt as it’s being laid. When it climbs over 300°F, your crew may have to slow down to allow the asphalt time to cool.
- Keep Track of Heat and Humidity
Ambient temperature includes the actual thermometer reading plus sun and wind. Once the outside air temperature climbs into triple digits, asphalt takes longer to cure and is at risk of problems down the road. Asphalt also takes longer to cure in high humidity.
- Maintain Equipment
High temperatures take a toll on equipment. Check all equipment beforehand and allow time for it to cool between use if necessary.
The heat can make it difficult for materials and machines, but it’s also challenging for workers. Be sure to follow safety measures when working in high temperatures to avoid heat-related illnesses.
- Work early or late in the day and avoid the hottest part of the day.
- Hydrate with water and electrolyte drinks. Take breaks frequently.
- Protect your skin with sunscreen, long sleeve shirts, wide-brimmed hats, and tinted glasses.
- Find or create shade with sunshades and umbrellas.
- Cool off periodically with fans or air conditioning, whether it’s taking a break indoors or inside an air-conditioned vehicle or machine.
The Occupational Safety and Health Administration (OSHA) maintains guidelines for operating safely in extreme heat.
While the work doesn’t stop this summer, try these tips to stay cool and safe.