How to cement a concrete surface

Video: How to Pour a Concrete Slab for Beginners DIY

Content

Steps
Method 1 of 2: Patching a Concrete Surface
Method 2 of 2: Applying a new patch over an existing one
Tips
What do you need

Concrete usually consists of cement, water, gravel and sand.This combination creates a very hard and durable material. However, cracks and other damage can appear in the concrete. Sealing such damage requires a number of materials, as concrete does not readily adhere to other concrete. The concrete mix and its construction depend on a chemical reaction that stops when the concrete dries. If you need to patch a concrete surface or pour new concrete over old concrete, you will need to purchase a strong binder as well as a special concrete patching mix. If precautions have been taken, then you can make a patch that will last for several decades.

Steps

Method 1 of 2: Patching a Concrete Surface

1 You should wait for a cool and cloudy day to repair damage in concrete. This is the best time for the concrete to adhere because the water will take longer to dry and the concrete will have more time to react with the cement.
2 Purchase a cementitious repair mortar. It can be bought in a ready-made mixed form or in separate components. If you have never tried to glue concrete to concrete before, then it is better to buy a ready-made mixture, where all you need to do is add water.
- Buying gravel, cement and sand separately will cost you significantly less than buying a ready-made mixture. If you are filling a deep hole, buy 1 inch (2.54 cm) gravel, otherwise go for very fine gravel.
- Mix dry materials in a bucket with a ratio of 3 parts gravel to 2 parts sand and 1.5 parts cement. Sometimes this ratio is indicated as 3: 2: 1. More cement will create a stronger material. A stronger reaction will occur between the water and the cement, resulting in more crystals and a stronger structure.
3 Sweep the concrete surface carefully. You must remove all stones, otherwise the bonding agent and cement will not reach the concrete surface.
4 After sweeping the surface of the concrete, you should wipe off any dust. Remove dust with a soft brush or blower, and do not forget about any dirt that has adhered to the surface of the concrete.
5 Flush out the concrete. Flush the concrete surface with a hose. Turn off the water in advance so that no standing water appears on the concrete.
- This will prevent the porous concrete from absorbing the moisture of the bonding agent and the concrete repair mixture.
6 Make cement paint. Mix Portland cement with water, available at some home improvement stores. Stir the two components until a homogeneous wet paint forms.
- You can also purchase an acrylic binder to use in place of your homemade cement paint. They are made of resin and can be added to the repair mix or applied as a cementitious paint. Follow the directions on the can or bottle exactly, as different substances have different instructions for use and drying times.
7 Take a paintbrush and apply a thin layer of cement paint to the old damp concrete. Do this before pouring new concrete onto old concrete surfaces.
8 Add water to the mix before applying your homemade or ready-mixed concrete repair mix. Stir well. Pour the repair mortar into holes and cracks, or apply a 1-inch layer of concrete on a flat surface.
9 Wipe the surface of the concrete with a wooden trowel. Apply concrete to the surface in a reciprocating motion until the gravel pieces sink under the surface. The sand and cement should go upstairs.
10 Let the water rise to the surface. After that, it will evaporate on its own. For a smoother finish, wait for the concrete to harden and become flexible, then apply with a metal trowel.
11 Cover the fresh patch with plastic wrap while it dries. This will keep as much water as possible inside the mortar, making the new concrete adhere better to the old one.
12 Spray new concrete with water every day for a week. This will prolong the chemical reaction and make the new concrete more robust.

Method 2 of 2: Applying a new patch over an existing one

This method works best if someone can help you mix and clean the concrete. Do not use this method on large areas until you have practiced and achieved good results on small areas.

1 Dilute Polybond adhesive in water, in a ratio of 1: 4.
2 Add dry cement powder cleaning mix.
3 Stir until you get a slurry.
4 Apply this cement paste to the old patch.
5 Pour new concrete while it is still wet.
6 Continue applying cement paste over the patch.
7 Finish applying the concrete as you normally would.

Tips

Cover new concrete if possible to block out the sun. Otherwise, the sun will dry out the water, making the bond in the concrete weaker.
To repair microcracks in concrete, you do not need to resort to cement paint and concrete repair mixture. You can seal these cracks with a thick paste of Portlea cement and water.
Achieving a smooth finish on concrete is difficult. It takes practice to get the perfect look. If the work is big, consider hiring a specialist.
If you are trying to fix an uphill or corner of a sidewalk or road, you should use reinforced steel rods or rebar to reinforce the new concrete and glue the two materials together. Consult your tool store for rod sizes for your project.
When working with wet concrete, always wear clothes that you don't mind ruining. The materials and mixing process can be quite messy.