What IS 383:2016 covers
IS 383:2016, titled Coarse and Fine Aggregate for Concrete — Specification, is the reference document that tells suppliers and engineers what properties aggregate must meet to be used in concrete. It is the third revision of the standard and it made room for manufactured sand and recycled aggregate alongside natural material. When a supplier says a product "conforms to IS 383", they are claiming the material's size, shape, cleanliness and strength fall inside the limits the standard sets. It is worth understanding those limits so you can ask the right questions.
Grading: the size distribution that matters most
Grading is the mix of particle sizes in a batch, measured by passing the material through a stack of sieves. It matters because a well-graded aggregate packs together with fewer voids, which means a stronger, more workable concrete that uses cement efficiently. For coarse aggregate, the standard defines nominal sizes — the familiar 6mm, 12mm, 20mm, 40mm and 53mm blue metal — and gives the percentage that should pass each sieve for that nominal size. A "20mm" aggregate is not all 20mm stones; it is a graded blend with most particles below 20mm and a controlled amount of smaller sizes.
The four properties buyers hear about
| Property | What it means | Why you care |
|---|---|---|
| Grading | Distribution of particle sizes across sieves | Controls packing, workability and cement demand |
| Flakiness index | Share of flat, elongated particles | Flaky stone is weaker and reduces workability; the standard caps it |
| Aggregate impact value (AIV) | Resistance to sudden shock loading | A measure of toughness for aggregate used under traffic and load |
| Water absorption | How much water the stone soaks up | Affects the water added at the mixer and the durability of the mix |
Flakiness is important because flat particles break more easily and interlock poorly. Impact value indicates how well the stone survives repeated shock, which is why it is watched closely for pavements. Water absorption is not just a durability question; porous aggregate pulls water out of the mix, so batching corrections are needed to keep the water-cement ratio right.
Fine aggregate and the sand zones
IS 383 also grades fine aggregate — sand — into four grading zones, from the coarsest (Zone I) to the finest (Zone IV). Our washed M-Sand is produced to Zone II, which is the general-purpose band widely used for structural concrete. The zone is decided by how much sand passes the 600-micron sieve, among other checks. For a fuller comparison of which zone suits which job, see our guide on Zone II versus Zone III sand.
Deleterious materials and cleanliness
The standard also limits "deleterious" content — clay lumps, silt, organic matter and other fines that weaken the bond between cement paste and aggregate. This is one practical reason manufactured sand is washed: washing removes the excess very fine material so the finished product stays within the limits. Clean, well-graded aggregate is simply easier to work with and gives more consistent results batch to batch.
What to ask your supplier
- Which nominal size and grading? Confirm the coarse aggregate size matches your mix design.
- What zone is the M-Sand? For most structural work you want Zone II.
- Is the material tested? Ask whether grading, flakiness, impact value and absorption are checked against IS 383.
- Is the sand washed? Washing controls the fines and keeps silt within limits.
Understanding the standard turns a vague "good quality" claim into specific, checkable properties. When you know the size and zone you need, see the pricing page or request a quote, and browse the full materials range to match products to your mix.
Quick answers
What is IS 383:2016?
It is the Indian Standard specification for coarse and fine aggregate used in concrete. It defines the grading, shape, cleanliness and strength properties that aggregate must meet, and its 2016 revision also recognised manufactured and recycled aggregate.
Does '20mm aggregate' mean every stone is 20mm?
No. A 20mm nominal aggregate is a graded blend with a controlled range of sizes, most below 20mm. IS 383 sets the percentage that should pass each sieve so the material packs well and uses cement efficiently.
What is the flakiness index?
It is the proportion of flat, elongated particles in the aggregate. Flaky stone is weaker and reduces workability, so IS 383 caps how much is allowed.
Which sand zone does M-Sand belong to?
Our washed M-Sand is produced to IS 383 Zone II, the general-purpose grading band widely used for structural concrete. The zone is set mainly by how much sand passes the 600-micron sieve.