Concrete is normally mixed by any two methods, based on the requirement as per quality and quantity of concrete required. For mass concrete, where good quality of concrete is required, a mechanical mixer is used, while where quality control is not of much importance and the quantity of concrete required is less, mixing by hand is employed.
In this article we are going to be looking mixing concrete by hand in do-it-yourself (DIY) projects in and around the home for example when constructing patios, fence posts, flooring, footers, and slabs or creating a walkway, a durable countertop, bathroom vanity tops, or a stylish weather-resistant planter.
You will need sand, cement, coarse aggregate, or dry concrete mix and a bucket, water, and a shovel. Also note that concrete mix reacts with water and that includes the moisture in your eyes, lungs, and skin, and this can cause burns which is why you will also need waterproof gloves, splash-resistant goggles, and a dust mask to keep safe.
The 4 simple steps when mixing concrete by hand
- Find a smooth, clean, and water-tight platform of suitable size e.g. a concrete platform, a brick floor, a wheelbarrow, or any other impervious platform of your own choice. Spread measured quantity of sand in the platform evenly.
- Dump the required quantity of the sand and spread evenly as well. Now mix the sand and cement using a spade by turning the mixture over and over again until it is of even color throughout and free from streaks.
- Spread out the sand cement mixture and on its top, spread a measured quantity of coarse aggregate. A general mix will be 1 part of cement with 2 parts of sand and 3 parts of coarse aggregate. Mix the whole mass at least three times by shoveling and turning over by twist from center to side, then back to the center, and again to the sides.
- Make a hollow in the middle of the mixed pile and add three-quarters of the total quantity of required water while the materials are turned in towards the center with spades. Add the remaining by water can, slowly turning the whole mixture over and over again until a uniform color and consistency are obtained throughout the pile. The water quantity should be determined with where you want to use the concrete. If you don’t want it too fluid add less water. If you feel you have added too much water just add in a little more sand and cement.
The concrete mixing process using readymade concrete mix
Readymix concrete comes pre-mixed just like those premix cake recipes in which all you do is add water. If you are using a readymade concrete mix, find a smooth, clean, and water-tight platform of suitable size e.g. a concrete platform, a brick floor, a wheelbarrow, mixing trough, etc. as mentioned above. Place the concrete bag in the platform or mixing trough or wheelbarrow and cut along the width of the bag. Stand upwind and lift both ends gradually to empty it.
Make a hollow in the center of the powdered mix and pour in two-thirds of the water specified in the instructions. Push and pull the mix until the water has been absorbed. Gradually add the remaining amount of water and continue mixing the concrete until it’s at an even consistency.
To test your concrete, cut the bottom off a plastic or paper cup and shape the container into a cone. Scoop up enough concrete to fill the cone, then empty the cone onto a flat surface.
If the concrete collapses to about half the height of the cone, you’re ready to go. But if it loses none of its height, i.e. if it doesn’t slump at all, add some more water, and if the concrete collapses considerably farther than half the height of the cone, you’ve added too much water and must compensate with additional mix.
Immediately after pouring the concrete, clean the tools used and the platform or mixing trough or wheelbarrow, unless you will be mixing up more concrete.