Summer heat poses tough problems for concrete contractors. Most pours begin in the morning when temperatures are cooler, but as the sun climbs the concrete has a tendency to set faster on top than on bottom. Not good. The following products and techniques will help you control your set time when the heat is on. Trust us, they’ll go a long way in keeping you cool!
WHY: Use it to extend your concrete set time. Important: Don’t rely on plant-batched retarders alone; part of their life is used up in transit time meaning you may abruptly lose the retardation when you need it most — near the end of the job.
HOW: Pour out three yards of a nine cubic yard truck with no retarder; add three bags of Mini Delay Set to the remaining six yards; then add another bag or two to pour out the remaining three cubic yards.
WHY: A Fritz-Pak product, Control Finish blends super plasticizer and retarder in a powder form. Use Control Finish when you need more moisture at the surface to balance your set time. Control Finish will allow the bottom to “catch up” when the top seems to be drying out — really helpful with color hardener.
HOW: Dump one bag of Control Finish into a pump-up sprayer, add water, shake and apply sparingly after screeding or after the first wood bull float pass. Use the bull float to work the control finish into the surface. The surface will be plasticized more than once without affecting the bottom set or compromising the strength of your slab. Remember — apply sparingly!
WHY: Supercizer 5 is a High Range Water-Reducing Superplasticizer. It increases flow and improves workability, and allows you to reduce the amount of water in your mix by up to 25%. Addition of this product greatly increases the ease of placement, allowing you to focus your efforts
HOW: Calculate the number of bags to use. Use one 1.75 lb bag per yard of concrete. When the job site is ready add Supercizer 5. Remove the protective outer bags and place the entire inner water-soluble bags directly into the concrete in the mixer while it is running. Mix on high speed for 5-7 minutes to ensure the product is evenly dispersed. Add color, followed by other admixtures, if using them.