All you need to know about DIY concrete mixing: 3:1 method of mixing concretes
The best overall mix for a DIY enthusiast to memorize and use is a simple 3:1 mortar mix. By using three parts sand and one part mortar you can create the strongest concrete possible as well as concrete that is easy to finish and detail with designs, templates or stamps. By not using the gravel the mortar will have a smoother overall consistency, but will ultimately occupy less volume than concrete made using gravel as well. If you are pouring very large volumes of concrete the gravel could prove to be cost effective however for most DIY projects a 3:1 mortar mix is the way to go.
The sand that you need to use for a 3:1 mortar mix should be sharp sand, or masonry sand or jointing sand. Each place that you purchase sand will use a different term so it can be confusing when shopping. All that you need to remember is to avoid play sand. Play sand is sand that has been washed and sterilized (this is ok) and then tumbled to soften all the edges of the individual sand grains (this is bad).
The sharp edges of the sand help to hold together the concrete mix better than the rounded edges of the tumbled sand. Ideally you would like to find sand from landscape supply stores which will sell to you by the cubic yard. With a strong trailer you can pick up as much sand as you could possibly need for next to nothing – plus the quality of the sand for making cement will be very high.
The applications for a DIY enthusiast to use a 3:1 mortar mix are huge. Everything from fixing broken outdoor steps and stairs, driveways, patios, decks, ponds, waterfalls, artificial rock, statues and much more is possible with a simple mix of sand, cement and water.
Start with small concrete projects to get a better feel and understanding for how to work with concrete. Since concrete is so popular world wide, and is a highly advanced science, you will never run out of interesting concrete applications to learn about or try. Combined with being the most affordable construction material on the planet and readily available everywhere – learning to mix basic concrete recipes is a fundamental DIY project.