Here’s a detailed procedure for laying concrete, from site clearing to finishing, along with general pricing information for concrete per square meter. This process assumes standard concrete laying for civil works like driveways, kerb and gutter, or footpaths.
Procedure for Laying Concrete
1. Site Clearing and Preparation
- Objective: Ensure the site is clean and level before laying the concrete.
- Steps:
- Remove all vegetation, debris, or any obstacles from the site.
- Excavate the ground to the required depth, typically about 100-150mm, depending on the project requirements.
- Compact the soil using a mechanical compactor to create a stable foundation.
- If necessary, lay down a layer of compacted gravel or crushed rock (typically 75-100mm) to improve drainage and foundation stability.
2. Formwork Installation
- Objective: Set up a mold or boundary for the concrete pour.
- Steps:
- Install wooden or metal formwork to shape the concrete. Ensure it is secure and level.
- Use stakes or braces to reinforce the formwork, ensuring it remains in place during the pour.
- Apply a release agent to the inside of the formwork to prevent concrete from sticking when removed.
3. Reinforcement
- Objective: Increase the strength of the concrete.
- Steps:
- Lay steel reinforcement bars (rebar) or a wire mesh within the formwork, ensuring it is elevated off the ground with small spacers to stay in the middle of the slab.
- Ensure the reinforcement is adequately spaced and secured for the type of load the concrete will bear.
4. Mixing and Pouring the Concrete
- Objective: Properly mix and pour the concrete for a strong, even surface.
- Steps:
- Mix the concrete on-site using a concrete mixer, or order ready-mixed concrete from a supplier. The typical mix is 20MPa for residential work or 25-32MPa for more heavy-duty surfaces.
- Pour the concrete into the formwork, starting from one corner and working across.
- Use shovels, rakes, or vibrators to spread the concrete evenly and eliminate any air pockets.
5. Levelling and Screeding
- Objective: Achieve a flat and smooth surface.
- Steps:
- Once poured, use a straight-edged board or a screed to level the surface by moving it across the formwork, dragging excess concrete along and filling any low spots.
- Repeat this process until the concrete is uniformly level.
6. Floating
- Objective: Create a smooth finish and remove surface imperfections.
- Steps:
- After the initial setting, use a bull float or magnesium float to smooth the surface further. This process pushes the aggregate slightly below the surface, creating a finer top layer.
- Ensure the surface remains wet enough to float without leaving marks.
7. Finishing
- Objective: Finalize the surface texture based on the project’s requirements.
- Steps:
- For a smooth finish, continue troweling the surface using hand tools.
- For a non-slip finish, use a broom to apply a light texture before the concrete fully hardens (broom finish).
- For decorative finishes, apply patterns or use colored concrete for aesthetic purposes.
8. Curing
- Objective: Ensure proper curing for long-term strength.
- Steps:
- Keep the surface damp by applying a curing compound or by misting water on the surface for the first few days.
- Cover the slab with a plastic sheet to maintain moisture.
- Allow the concrete to cure for at least 7 days, though full curing takes about 28 days.
9. Formwork Removal and Clean-Up
- Objective: Finish the job by removing supports and cleaning the area.
- Steps:
- Carefully remove the formwork after the concrete has hardened (typically 24-48 hours after pouring).
- Clean the surrounding area and dispose of any debris.
- Inspect the concrete for any cracks or imperfections that need to be repaired.
Pricing of Concrete per Square Meter
The price of concrete varies depending on the region, supplier, mix type, and quantity. In South Australia, the typical cost per square meter for standard 100mm thick concrete slabs, including supply and installation, ranges between $70 to $150 per m². Here’s a breakdown:
- Basic concrete (plain): $70 – $100 per m²
- Reinforced concrete: $100 – $130 per m²
- Decorative or exposed aggregate concrete: $120 – $150+ per m²
These prices include materials (concrete, reinforcement), labor, and finishing, but exclude site preparation, excavation, or additional complexities like color or stamping.
Would you like more specific pricing details for your current projects?
