Today we will discuss concreting and how high temperatures affect it. The weather outside is frightful, and not at all in the way that the Christmas carol meant. Temperatures have been hitting record highs all over the country in the last few weeks. This time of year is full of sun and brutally hot summer days. We know how the summer heat affects asphalt (almost everyone has seen the summer glisten and sizzle of hot asphalt), but what effect does it have on concrete? A lot. Heat is an integral part of concreting because the process of concrete setting produces heat. Generally, you can expect that concrete will be about 18 degrees warmer than the surrounding air temperature. When that means it is 18 degrees hotter than super hot, it can lead to four major concreting issues.
During hot temperatures, concrete will set faster. You might think that’s a good thing, but it decreases the amount of time you have to place and finish the concrete. For every 20-degree increase in temperature, you will see a corresponding 50% decrease in a set time. Faster set times can decrease the strength of the concrete and increase the likelihood of cracking. If you’re rushing to beat the heat clock, you are more likely to make mistakes as well.
Moisture and concrete can sometimes be a bad combination, but when concreting, you have to have water in the mix to pour it. When the weather is hot, the moisture content of the concrete evaporates more quickly, especially from the surface. As a result, the surface can become cracked. However, you can prevent this by covering the concrete with a plastic sheet. It is also a good idea to wet down the substrates during scorching weather before you pour any concrete.
The heat causes rapid evaporation at the surface and causes concrete to set more quickly, both of which can lead to cracking. The cracking of concrete often results in the differential of temperature or moisture that occurs on hot days. To prevent it, try to make sure substrates are moist and cool and keep the temperature down while the concrete is setting.
High heat leads to faster slump loss which decreases the strength of the concrete. Some steps that will help you avoid this include keeping the batches of concrete as cool as possible. Keep your concreting equipment in the shade when possible, use wet burlap to cool equipment and lines, and if possible, use refrigerated water to mix the batches.
Concrete Visions Will Get The Job Done Right
Concrete Visions has been working with clients for over 25 years. Our G&M Services installers are certified with the industry’s major firestop product manufacturers. As part of our firestop service, we can assess abnormal field conditions and, with the manufacturer’s technical support assistance, provide engineering judgments in a timely fashion to comply with contract specifications. Our Field Mechanics undergo ongoing training, including mandatory monthly safety meetings, weekly Toolbox Talks where safety and equipment information is shred, and trainings on safe work standards and safety best practices.