As summer unfolds, construction projects ramp up, spurred by the promise of longer daylight hours and warmer temperatures. At North Port Concrete, our teams eagerly seize the season’s opportunities to maximize productivity before the cooler months approach.
While summer typically offers fewer concrete challenges, soaring temperatures can present their own set of issues. When faced with temperatures nearing 90 degrees, adjustments to the concrete mix and installation process become necessary to ensure a successful pour.
In this guide, we delve into the essential steps required to navigate the complexities of pouring concrete in hot weather.
Navigating the Warm Weather Concrete Challenges
Embraced by many, the balmy summer months often pose challenges when it comes to pouring concrete in hot weather.
Optimal concrete curing typically occurs within the moderate temperature range of 70° to 80° F. However, as the mercury climbs towards 90° F, complications arise. In the realm of concrete, hot weather encompasses more than just elevated temperatures.
Days characterized by low relative humidity and high wind speeds are also categorized as “hot weather,” contributing to potential issues during concrete pours.
Navigating the Finishing Challenges
Concrete’s rapid setting in hot weather poses a significant challenge, as it leaves little time for leveling and finishing before it solidifies.
On scorching days, achieving a smooth and level finish becomes notably arduous. Without proper precautions, your completed slab is prone to surface irregularities and unevenness.
Assessing the Influence of Heat and Humidity
During summertime, elevated temperatures significantly affect both the setting time and strength of your concrete mix. In certain regions, summers are notorious for their stifling humidity levels.
Though the heat alone might not be excessive, the blend of heightened temperatures and moisture-laden air can present obstacles during a concrete pour.
Without adequate measures, the combined impact of heat and humidity can compromise the strength and durability of your newly poured concrete.
Accelerated Setting Time and Strength Reduction
In warmer temperatures, the setting time of freshly poured concrete significantly decreases, necessitating swift action in placing control joints strategically to manage random cracking as the material hardens and contracts.
However, the reduced setting time poses a challenge, as there is limited opportunity to place these joints accurately before the mix solidifies.
Concurrently, the hydration process crucial for the slab’s strength occurs more rapidly in hotter conditions. Unlike cooler concrete, which benefits from extended hydration time for the formation of strong crystals, the accelerated process in higher temperatures leaves less time for crystal formation and, consequently, compromises compressive strength.
To mitigate these effects, proactive measures must be implemented to uphold the strength and durability of concrete poured in hot weather.
Drying Shrinkage and Evaporation Concerns
Drying shrinkage poses a notable challenge, particularly in hot weather conditions, exacerbating the difference in volume between a wet and dry slab.
The elevated temperatures accelerate evaporation rates, significantly impacting the shrinkage of the slab. Moreover, the temptation to add excess water to the mixture to counteract the heat intensifies this issue, as a wetter mix leads to a greater volume change upon setting.
Heightened Risk of Surface Cracking
Under the influence of hot weather, wind, and arid conditions, evaporation rates soar, heightening the risk to the surface layer of your concrete slab.
The accelerated evaporation process leaches water from the surface layer, potentially rendering the mix excessively dry and significantly increasing susceptibility to surface cracking.
