Even though we are getting ready to turn the calendar to September and children have headed back to school, the end of summer doesn’t necessarily mean the end of high temperatures. It is hot. Really, really hot.
During the last few weeks, we have seen unseasonably high temperatures across the United States. This combination of conditions (high temperature and low humidity) can make placing concrete a challenge. A recent article in Concrete Contractor provided tips to successfully complete a project in hot weather.
Tip #1: Understand what “hot weather” means. According to the American Concrete Institute (ACI) Committee 305, hot weather is defined as any combination of high ambient temperature, high concrete temperature (80 degrees Fahrenheit), low relative humidity, wind speed and solar radiation that can impair the quality of fresh or hardened concrete.
Tip #2: Know the potential impacts that hot weather can have on concrete. Issues include:
High temperatures and low humidity increase the frequency of cracking.
Concrete hardens faster in hot weather.
Greater demand for water.
Increased difficulty in handling, placing, consolidating and finishing.
For more tips, read the entire article here.
Follow these precautions to mitigate the negative impacts of hot weather on your next project
Plan ahead. Have all forms, equipment and workers ready to handle concrete, especially during the first delivery of the day to avoid delays.
Utilize materials and mix proportions that perform well in hot weather conditions. Use a concrete consistency that allows rapid placement and consolidation.
Reduce the times for transport, placing and finishing as much as possible.
When the weather is extremely hot, restrict placement to early morning, evening or nighttime hours.
Staying cool on the jobsite
While its important to know how to successfully work with concrete during hot weather, its more important to keep your crews cool while on the job site. Make sure your crews:
Drink more water, not caffeine!
Take breaks in the shade
Wear light-colored, lightweight clothing
Wear sunscreen and sunglasses
Regularly train employees to recognize the signs of heat stress and prevent as well as treat it. Encourage the use of the buddy system to ensure co-workers are looking out for each other. Finally, download OSHA’s Heat Safety Tool app, which allows anyone to calculate the heat index for a jobsite and the risk level for outdoor workers.
To learn more about staying cool on the jobsite, check out OSHA’s Water. Rest. Shade. (#WaterRestShade) campaign.