This guide on how to mix concrete places emphasis on finding the proper consistency for your mixture.
Guide to Concrete (Creative Publishing International, 2008) takes readers through some of the most popular home concrete and masonry projects. Endorsed by Quikrete, this book includes tips and expert advice that can help readers save hundreds or thousands of dollars in their DIY home projects. Excerpted from “Tools and Techniques,” this guide on how to mix concrete includes tips on using a power mixer.
You can purchase this book from the MOTHER EARTH NEWS store: Guide to Concrete.
|A good mixture is crucial to any successful concrete project. Properly mixed concrete is damp enough to form in your hand when you squeeze, and dry enough to hold its shape. If the mixture is too dry, the aggregate will be difficult to work with, and will not smooth out easily to produce an even, finished appearance. A wet mixture will slide off the trowel and may cause cracking and other defects in the finished surface.|
• Power mixer
• Wheelbarrow or mortar box
• 5 gallon bucket
• Safety glasses
• Particle mask
• Concrete mix
• Additives as desired
When mixing concrete on-site, purchase bags of dry premixed concrete and simply add water. Follow the instructions carefully and take note of exactly how much water you add so the concrete will be uniform from one batch to the next. For smaller projects, mix the concrete in a wheelbarrow or mortar box. For larger projects, rent or buy a power mixer. Be aware that most power mixers should not be filled more than half full.
When mixing concrete, the more water you add, the weaker the concrete will become. Mix the concrete only until all of the dry ingredients are moistened. Don’t overwork it; three to five minutes should be enough.
|1. Empty premixed concrete bags into a mortar box or wheelbarrow. Form a hollow in the mound of dry mix, and then pour water into the hollow. Start with 3/4 of the expected water amount per 80 pound bag.
||2. Work with a hoe, continuing to add water until a good consistency is achieved. Clear out any dry pockets from the corners. Do not overwork the mix. Also, keep track of how much water you use in the first batch so you will have a reliable recipe for subsequent batches.
|1. Fill a bucket with 3/4 gallons of water for each 80 pound bag of concrete you will use in the batch (for most power mixers, three bags is workable). Pour in half the water. Before you start power-mixing, review the operating instructions carefully.
||2. Add all of the dry ingredients, then mix for 1 minute. Pour in water as needed until the proper consistency is achieved, and mix for 3 to 5 minutes. Pivot the mixing drum to empty the concrete into a wheelbarrow. Rinse out the drum immediately.