Concrete has many different uses that most people wouldn’t even think possible, but to be able to comprehend the really complicated projects you need to learn the basics of concrete, cement and mortar. This article will give you in-depth knowledge on how to mix concrete, some frequently asked questions and their answers, and will finish off with a guide on how you can use your newfound knowledge of concrete and cement mixers to create a beautiful countertop. The first thing that any aspiring DIY expert will need to learn is how to properly mix together concrete when they don’t have access to cement mixers.
To mix concrete yourself the tools you will need are a wheelbarrow, a shovel, a measuring bucket, gloves, dust masks and a stiff bristle brush. The wheelbarrow will be used for the transportation of your aggregates and final concrete mixture, the shovel for moving into the wheelbarrow and mixing and the bucket is to ensure that all your aggregates are the correct ratios. Safety must always be a top priority so gloves must be worn whenever working concrete as well as a dust mask to prevent inhalation of cement dust.
The brush will be used for cleaning all tools used during the mixing and pouring process as any concrete left on them will cause erosion. Now that you have all your tools together you need to look at what aggregates you will be using. Aggregates are the cement, sand and gravel that you are using to create your concrete and they can have a massive impact on the final result.
Different cements can be used for different circumstances, have different curing times and require different ratios of water and other aggregates to be effective. Be sure to do proper research and possibly even speak to the workers at your local hardware store to ensure that you are using the correct cement for your specific purposes. For instance, a concrete mixture for a wall inside of a house that needs to be smooth will be different to that of a driveway that needs to just be durable.
First you will need to designate an area specifically for mixing concrete and prepare it accordingly, it is a good idea to lay down some old tarpaulin or sheet board to keep the mess to a minimum. Next, measure out the appropriate amount of water for your pour and pour it into the wheelbarrow. Adding the water first and then the other aggregates on top allows you to do the whole process faster and reduces the amount of cement dust flying into the air.
Be careful not to use too much water in your mixture otherwise the concrete will not be as strong as the bag advertises. Next pour in your cement but not all at once, pour in about two thirds of the cement and mix it until everything is saturated. Then pour in the rest, this again will reduce the amount of dust flying in the air and help ensure a consistent mixture. If you are using cement mixers you can pour in all the cement at once.
Next add in your sand and gravel in properly measured ratios and continue mixing until the whole mixture is consistent and no more dry parts are left. If you feel like your mixture is too runny, add some more cement mixture from another bag until it reaches a consistency you are happy with. It’s always a good idea to get more cement than you need just in case you have miscalculated.
Next you will need to transport your concrete mixture to where you intend to pour it and either tip your wheelbarrow over or use your shovel to place the concrete into the pour area. Next you can use a tool like a concrete vibrator or even something as simple as an old piece of work to slowly work all of the air out of the concrete. Using that same piece of wood or even a scraper you can then smooth out the surface of your new concrete surface and allow the curing process to begin.
Finally, using the brush you will need to clean all of the concrete off of any tools that were used as well as yourself. Remember to rinse out your wheelbarrow and shovel as soon as possible or the concrete will stain them or even make them unusable. A good idea is to do this cleaning in your designated mixing area, as any concrete that spills off could damage your walls or driveway if left there.
Concrete and Cement Mixers Common Questions
One common question is whether or not you can pour on top of existing concrete, or if you should demolish and start again from the beginning. The simple answer is that yes, you can, but there are some things you should definitely consider before doing so. You need to ensure that the original concrete that you are pouring on is still structurally sound and if there are any cracks that may seep into your new pour.
If the slab is heaving or has large cracks in a specific area you should inspect and find out why this has happened. Is it natural elements and time or is there something wrong with the ground underneath, the area as a whole or the original concrete itself? Things like this will not only affect the concrete if you pour on top but also any new pour if you decide to demolish and use cement mixers to start again.
If the concrete seems solid and you simply want a new coat before laying out new permanent outdoor fixtures, at minimum you should pour a new slab of 6cm. Any smaller and the slab could be thinner than some of the rocks in the gravel that you are using and the strength of the new pour will be greatly reduced. If the slab is poured too thin it could also not allow the concrete to cure properly and it will simply dry out and turn back into dust, or at the very least gain large cracks.
Another question is if you can make concrete in cement mixers without using gravel and the answer to that is also yes and this mixture is known as mortar mix. This mixture is not as strong as concrete as the gravel is what gives it a large portion of its strength and durability. Mortar mix is mainly used as a very strong glue to hold bricks and stone blocks together.
A final question is where can you learn more about cement mixers and how to properly work with concrete. The first and easiest route would be to simply speak to the workers at your local building or hardware store as they know everything about the products that they stock and sell. Another route would be approaching a construction site and asking to see how cement mixers and large pours are done on a daily basis, their experience can be used for your smaller projects.
Using Cement Mixers and Concrete to Create a Countertop
The first thing you will need to do is create the mould for your new countertop, to do this you will need to measure the cabinets that it will rest on (or your existing countertop if you are doing a renovation) and add an extra 5cm of overhang. Your mould is very important as any imperfections will be shown on the surface of the final concrete product when it has finished curing. Once you have your measurements, create your mould out of wood or consider hiring a carpenter if that is not your area of expertise.
Make sure to leave adequate cutouts if you have sinks or other appliances within the countertop and ensure there is no sawdust left within before pouring. Also make sure that the mould is properly sealed so that no leakages can occur. A layer of silicone along all the sides will ensure no concrete comes out and no air seeps in.
Either build a frame or find a level floor for the mould to rest on while you pour as this will determine how level your final countertop will be. Mix up your concrete using cement mixers or the steps shown above, cement mixers can be rented for short periods of time if you want to ensure quality. Pour your concrete into the mould and allow it to set and eventually cure, remember that this will take a few days and you need to be patient to ensure the best quality.
When the concrete has finished curing you can remove the mould and admire your new concrete countertop. Be careful when removing the mould if it seems stubborn to make sure you don’t damage the surface and cause cracks. Try using a hammer to pull out the nails or screw used to remove the sides or if you have someone to help you, try flipping the slap over slowly and let gravity help you remove it.
When the slab is removed from the mould you can use sandpaper or an electric grinder to further smooth out the edges and get a pristine surface. Remember to wear a dust mask at all times as this can be extremely toxic if breathed in and be prepared as this will use a lot of sandpaper to get a really smooth surface. When you are done sanding wipe the entire surface and the edges down with a damp rag to get rid of any loose debris that remains.
Finally, using eye, mouth and hand protection, create a solution of muriatic acid and water and use a sponge dipped in the solution to give the surface a thorough scrubbing. If you are doing this inside remember to open all windows and doors to create proper ventilation for the gasses. Rinse the slab with water afterwards to get rid of any acid and then allow it to dry completely.
Once the slab has dried completely apply at least 2 coats of a concrete sealer to ensure the smoothness stays for years to come. Work in long strokes when applying the sealer and allow the first coat to properly dry before applying the second. It is a good idea to keep applying coatings until the concrete no longer absorbs it.
Prepare the cabinet tops with a thick layer of silicone on all the edges that will make contact with the slab. Get help and slowly lower the slab into the desired space allowing it to make good contact with the silicone, make sure to place it exactly where you want it and don’t slide it around afterwards. This will create streaks of silicone and reduce how much is making contact between the concrete and the cabinets.