Concrete is among the strongest building materials on the market, but if not placed with care and attention, it can develop weak places that decrease its strength and endurance. One of those problems that can arise during larger pours is known as cold joints. Cold joints occur when the first layer of concrete sets up before the next layer is placed. This prevents the two layers from intermixing and opens the concrete up to honeycombing and water seepage.
How To Manage the Pour to Prevent Cold Joints
Since cold joints can increase the risk of voids and water damage and are generally just unpleasant to look at, the concrete crew needs to manage the pour in such a way that will help prevent them from happening. When pouring a slap, concrete placement should begin in the corner of the slab and work towards the center. When you start placing a new load, place it directly against the previous batch. If you’re pouring walls, beams, or working with IFC blocks, pour the concrete in 18-inch layers and use a vibrator to ensure the layers intermix. On hot days, you can also use a delayed set admixture, such as our Mini Delay set, to slow down the overall set time of the mix.
How Not to prevent Cold Joints
In warmer climates, it is all about keeping the heat from setting up the concrete before you, as the contractor, are ready.
Many times, especially when pouring slabs and concrete beams, it can be tempting to increase the slump by a couple of inches to help slow down the setting time. While this is a quick solution, it, unfortunately, lowers the overall strength of the concrete. This will result in cracks and damage that require significant repairs later on down the road.
Fritz-Pak has a Better Solution
In addition to properly managing the pouring of the concrete, adding Fritz-Pak’s Supercizer 2 is an easy, affordable way to prevent cold joints. This superplasticizer increases the slump of the concrete without changing the water-cement ratio. This ensures the concrete flows into all the crevices of the form while maintaining the strength of the mix. Supercizer 2 also has a delayed set component that will help the first batch or layer from setting up before you can place the next one.
Order Yours Today
So, whether you’re placing a large floor for a warehouse or garage, working with precast molds, or providing the concrete for an ICF home, Fritz-Pak’s Supercizer 2 can lower your stress levels and reduce the risk of unsightly, problematic cold joints. For more information or to order your case today, visit our online store at fritzpak.com/store.