Aggregates make up most of the volume of concrete. Their size, shape and cleanliness have a direct effect on strength and durability.
In a typical concrete mix, coarse and fine aggregates make up the largest part of the volume. That is why the quality of stone chips has such a strong influence on the finished structure.
Properties that matter
- Grading: a balanced range of sizes packs tightly and needs less cement paste.
- Shape: cubical stones interlock better than flaky or elongated pieces.
- Cleanliness: dust, clay or organic matter weakens the bond with cement.
- Strength: the stone itself must be hard and durable.
Good practice at site
- Store different sizes separately on a clean, hard surface.
- Keep material covered or away from mud and run-off.
- Follow the mix proportions given by your engineer.
- Use testing where the project requires it.
Using the right aggregates does not only improve strength; it also helps workability and can reduce cement use, which lowers cost.
