While there are alternatives to mixing concrete, utilising concrete mixers is by far the easiest method. Doing so will save you time and require less effort, and at the same time will allow you to mix greater quantities and thoroughly mix the materials. Using cement mixers lessens the chances of weak spots in the mixture, and allows you to get the job done quickly. To make your cement mixing experience simpler, in just a few minutes of reading, check out our easy guide to making concrete with concrete mixers.
What is concrete and what does it have to do with concrete mixers?
For those who are new on the cement and building scene, the intricacies of concrete and concrete mixers may seem foreign. In simple terms, concrete is a compound of cement, sand and stone, blended together thoroughly. The cement from your mixer is the binder that joins together the sand and stone effectively, giving concrete that easily recognisable strength and hold. On their own, a mixture of sand and stone would have absolutely no strength.
Concrete mixers, alternatively known as cement mixers, successfully mixes the above with water to make concrete which before drying is malleable and functions as the building material we know today. Before the invention and production of these machines, builders using concrete painstakingly mixed the materials by hand, adding an unbelievable amount of time onto building projects. The first cement mixers were built in the early 1900s, and since then have been aiding builders all over the world to complete projects timeously.
What you need to know about differently mixed concrete before using your concrete mixers
Diversifying the proportions of cement, sand and stone in your concrete mixers has a direct consequence on the form and strength of your concrete. The varied strengths control the amount of force the final and dried product can withstand without deteriorating. There are “recipes” referred to as “C” types that people use to specify the strength of different concrete mixes, which indicate the proportion of materials needed to create a concrete of a specific strength. The following is a quick run-down on two of the most common “C” types:
C20: This recipe serves as a general use mix, which is commonly used for making concrete pads, fixing posts, creating door steps and bases for your sheds and wendy-houses. It is mixed with 1 part cement, 2 parts sand and 4 parts stone.
C30: This recipe on the other hand is stronger in nature, and is mixed with 1 part cement, 3 part stone and 2 parts sand. It is suitable for thinner and more narrow slabs such as sidewalks.
What clothes do you need to mix concrete in your concrete mixers?
It is unwise and heavily discouraged to wear your every-day clothes while mixing cement in a mixer. For those who are using a mixer in a non-work and more relaxed setting, it may be tempting to throw on a T-shirt and jeans and work on your weekend project in style. However, if you wish to remain safe and avoid any visits to your doctor, you should consider donning the following personal protective equipment:
Gloves: wearing gloves will protect your hands from surface-level injury and abrasion while using your tools, as well as protect you from cement spillage (as cement can be an irritant to your skin).
Dust mask: putting on a dust mask may be a schlep, especially if it is hot and you are working in the sun. However, the mask serves to protect your lungs and as a result is highly important.
Safety glasses: arguably one of the most important pieces of personal protective equipment, safety glasses protect your eyes from splashes the concrete mixers may produce. Can you imagine getting concrete in your eyes and the havoc that may cause?
Steel toe shoes or boots: working with the aforementioned adequate footwear protects your feet from falling objects.
What tools do you need to mix concrete in your concrete mixers?
Although using cement mixers lessens the amount of effort needed to get the job done, you will still require the following tools to help you on your way:
- Three buckets. One bucket will be used for the sand and gravel, one for the cement and the other for water
- A barrel to hold water and fill up the water bucket easily
- A wheelbarrow to transport your freshly made concrete
- A spade.
Detailed steps on how to use your concrete mixers
Now that you know a bit about concrete mixers, you may be wondering how exactly you can make it. The following may serve as a guide to get you on your way, although extra research and training is always advised:
Measure your cement, sand and stone in three separate piles on the ground (doing so on a plastic sheet or plywood is advised if you wish to keep both the ground and your materials clean and uncontaminated.
Use a small barrel or wheelbarrow to hold water if you know that you will be creating several mixes. While some people prefer to use a hose to fill up water buckets, one can easily see how this will add extra time to the mixing process.
Start your concrete mixer!
Shovel in about half of the stone, and one quarter of your bucket of water. Because stone is abrasive in nature, it will help scratch off any wet and remaining concrete from earlier mixes that may still be stuck in the drum of your mixer.
Now, you will add your cement, the rest of the stone, and sand from your piles. When you add your sand and cement, watch closely for a bit to see how the mix is doing, and then add water accordingly so that the mixture is not too sloppy but also not too dry (which will be apparent if it begins to stick to the drum). If this is the case, never put the spade into the rotating drum, as the mixing spoons will catch the shovel and swing it around (likely whacking you in the face in the process). Turn the mixer off rather and use the spade to clear the sides of the barrel, while adding more water if necessary.
Leave the mix on full speed for approximately 3 minutes.
Next, reduce the speed and begin unloading the mixer into the wheelbarrow.
Now, a new mix can be started. Before this though, you must add water and stone if necessary to rinse the remaining concrete out of the drum. Do not worry about getting rid of the “slush” however, as it can be used in the next mix. Do not forget to wash all your tools before the concrete sets and dries on them.
How should you store cement?
As one of the key components of concrete, cement must be stored appropriately so that it remains effective when you load it into your concrete mixer, yet many people are unaware of how to correctly store the bags, however. Cement bags should be kept off the ground so as to prevent moisture from soaking into them. To do so you do not necessarily need a tall shelf, you can also utilise a pallet of wood or bricks to keep the bags slightly elevated. Alternatively, you can place the unopened bags inside plastic bags to seal them tight and protect them.
Cement should be used within 3 months of its manufacturing date which should be indicated on each bag. After this timeframe it can often become less effective. For this reason, refrain from buying cement bags in bulk and rather work out exactly how many you will need for your project so as not to waste any.
Dos and Don’ts when mixing concrete in concrete mixers
Mixing concrete incorrectly can put a hole in your pocket as well as waste precious time you needed for your building project. You should be aware of the following dos and do nots so as to avoid any unnecessary faux-pas:
Do not hurry when mixing concrete in your concrete mixers
This is a tough one and is often easier said than done. Tight building deadlines and unforeseen delays may result in people rushing to get the job done. However, going too fast is a sure way to both botch your mix as well as create an annoying mess while you are at it.
Double check your supplies
There are few more frustrating scenarios than starting a concrete mix only to find out that the bag of stone or sand you thought you had, is almost completely empty, for example. You run the risk of wasting the mixture you already have and incurring unnecessary costs. You need to ensure every time you plan to mix concrete that you have absolutely everything you may need. If that involves making a check list – so be it!
Do not “guesstimate” the proportion for your concrete mixer
It does not matter if you follow the above tip and have all your ingredients in check if you are just going to mix them incorrectly. There is a reason that concrete has worked so effectively all these years and remains one of the most widely used building mediums across the globe. Refrain from eyeballing the amount of each ingredient you use, and instead take the longer route of measuring the exact amounts out and placing them in piles on a work surface. In the long run, you can avoid fragile concrete and in the worst cases, failing structures which could result in tragedy.
Take safety precautions when using concrete mixers
Taking safety precautions seriously when using concrete mixers is a great way to avoid hospital visits and keep yourself and your employees safe while they work. There are several common accidents or safety hazards that you should be aware of:
Mixers toppling over: although this may seem an unlikely event, it is actually quite a common occurrence which could injure the operator and bystanders. This accident usually takes place when the mixer is operating on an unstable surface, or around debris or other objects that could suddenly move and push the mixer over. For this reason, the area around the mixture should always be scouted and cleared of any unnecessary objects before it is turned on. Further, the wheels of concrete mixers should be blocked so that they cannot roll.
Cement exposure: failure to wear a mask and proper personal protective equipment, in particular a dust mask, can result in breathing in harmful fumes and dust. Failure to wear gloves and long sleeves can result in cement or mixture coming into contact with the skin, which can often be abrasive and become an irritant.
Moving parts: because cement mixers are constantly moving when they are turned on and mixing cement, there is naturally the danger of injury as a result of the moving parts. Never attempt to clean the barrel with a spade or any other object while it is switched on, and refrain from wearing loose clothing that can become snared and caught in the machine.