While many industries flourish in warm climates, high temperatures and humidity also create a number of challenges for the construction industry. Hot, dry weather can lead to excessive surface moisture evaporation during concrete curing. Wind is also the enemy in this environment as it exacerbates the accelerated evaporation process. The result is shrinkage, cracking and finishing difficulties that can substantially reduce the concrete strength in your building or structure.
One of the best ways to avoid this is to keep the concrete cool. Cooling the mix by replacing part of the mixing water with ice will significantly lower the concrete’s temperature and decrease slump loss. On site equipment – from the mixers to the conveyor belts – should be kept shaded and as cool as possible to protect the concrete.Hot weather also impacts the setting time of concrete by accelerating the hydration and causing it to dry too quickly. Acceleration in the hydration process will increase slump loss, whereas retardation in the hydration process will decrease slump loss. To find the right balance, you can use an admixture to act as a set retarder to mitigate this process.
Dubai required hot weather concreting process
We used our Krystol Internal Membrane (KIM) product for a recent project in a hot and humid environment where the temperature often ran in the mid to high 40⁰C range. Although KIM’s primary function is to act as a concrete waterproofer, it also automatically enhances the durability of concrete. By managing the heat of hydration, KIM can reduce shrinkage and cracking by up to 25% and assist in internal curing which ultimately leads to a more durable and waterproofed concrete structure.
Construction of the Emirates Call Center in Dubai was running behind schedule and due to tight timelines, KIM was selected as the waterproofing system in place of membranes. The entire raft slab and vertical walls were cast with KIM dosed concrete, while the horizontal joints were waterproofed with the Krystol Waterstop System. This project was delivered on schedule in large part because of the efficiency of the hot weather concreting process assisted by Kryton’s KIM concrete waterproofing admixture.