Concrete

The Standard Mix Ratio

For general-purpose concrete, a common mix ratio is 1:6, which means one part cement to six parts ballast. This ratio is suitable for many applications, including garden paths, shed bases, and general landscaping projects.

Here’s a breakdown of what you’ll need for 1 cubic metre (1m3) of concrete using this ratio:

Cement: 230 kg

Ballast: 1,380 kg

Water: Approximately 150 litres (adjust as needed)

Keep in mind that these are approximate figures and may need slight adjustments based on the specific materials you’re using and the desired consistency of your mix.

Comparison of Mix Ratios

Different projects may require different concrete strengths. Here’s a comparison table of common mix ratios and their applications:

Mix Ratio cement to ballast:

1:6 General purpose, paths, shed bases

1:5 Driveways, floor slabs

1:4 Structural concrete, foundations

1:3 High-strength applications

Tips for Mixing and Pouring

Mix on a clean, flat surface or use a cement mixer for larger jobs.

Add water gradually and mix thoroughly to avoid a too-wet mix.

Only mix as much as you can use within an hour.

Dampen the area before pouring to prevent moisture loss.

Level and smooth the concrete quickly before it starts to set.

All-in-one ballast is convenient and works well for most general-purpose applications. For specialised projects, using separate sand and gravel allows for more precise control over the mix.

Setting and Curing Times

Concrete typically takes about 24-48 hours to set initially, but full curing can take up to 28 days. It’s usually safe to walk on after 24-48 hours, depending on conditions.