M-50 or M-55, 80 or 120 mm? Choosing paver blocks for container yards and ports
The question I am asked most by engineers planning a yard is: which grade, and which thickness? Here is the short answer, and the actual specifications from four heavy-duty pavements we have made and laid.
The short answer
On every heavy-duty pavement we have built, the specification has sat between M-50 and M-55, and between 80 mm and 120 mm thick:
- 80 mm, M-50: port internal roads, truck parking and a steel stackyard (Dhamra Port).
- 100 mm, M-50: container yards and inland container depots (Balmer Lawrie, Visakhapatnam, and nine CONCOR ICDs).
- 120 mm, M-55: container storage and handling areas at a dry port (Jalna).
The grade and thickness for your job should come from your pavement design and specification, not from a supplier's catalogue. What I can tell you is what these pavements were, and what made them work.
Four heavy-duty pavements, side by side
| Project | What it carries | Block | Thickness | Grade & standard | Area |
|---|---|---|---|---|---|
| Dhamra Port, Odisha Adani Ports, 2021 | Internal roads, truck parking, steel stackyard | Unipaver, 250 × 125 mm, herringbone at 45° | 80 mm | M-50, BS 6717 | About 2,50,000 sqm (80 lakh blocks, made at site) |
| Jalna Dry Port, Maharashtra IPRCL, 2021 | Container storage and handling, logistics park | Unipaver | 120 mm | M-55, IS 15658 | 40,000 sqm in 6 months, made at site |
| Balmer Lawrie Container Depot, Visakhapatnam 2017 | Container yard operational areas | Brick shape, 100 × 200 mm | 100 mm | M-50, IS 15658 | 65,000 sqm, made at site |
| CONCOR inland container depots Nine ICDs | Container yards | Brick shape, 100 × 200 mm | 100 mm | M-50, IS 15658 | Supplied and laid |
What the table tells you
Grade moved less than thickness. Three of the four are M-50; Jalna went to M-55. All four sit at the top of the range we make (M30 to M55). For heavy-duty yards, the real discussion is usually about thickness, the base and the laying, not about going higher on grade.
Thickness followed the job. At Dhamra the specification was 80 mm for internal roads, truck parking and the steel stackyard. At Jalna it was 120 mm for container storage and handling. In both cases the specification was set by the client's engineers; our job was to make it, lay it and prove it.
Shape and pattern both matter. Dhamra and Jalna used unipavers (zigzag); Balmer Lawrie and the CONCOR depots used the 100 × 200 mm brick shape. At Dhamra the blocks were laid in herringbone at 45°, the pattern that locks best under traffic that turns, brakes and accelerates.
The standard is whatever the project specifies. Most of our work is to IS 15658. Dhamra was tested to BS 6717 because that is what the project specified.
Grade is only half of it
On a depot, the difference between a pavement that lasts and one that needs attention within a year is often not the block. It is the base, the sand bed, the joints and the edges.
- Joints. Jointing sand spread and brushed until every joint is full, before the area takes traffic. A half-filled joint lets blocks rock, chip and go wavy. We filmed this step at Jalna because it is the one contractors most often rush.
- Levels and lines. Laid to line, level and camber so water runs off. On a coastal yard like Visakhapatnam, water that sits on the pavement does the sub-base no favours.
- Edge restraints. Kerbs and edges hold the field of blocks together. Without them, the pavement slowly spreads under traffic.
- The base and the bed. A properly prepared base and an even sand bed let every block carry its share of the load.
How these pavements were proven
Before handover, the finished pavements at Dhamra and Jalna were put through the vibratory roller test, and both came through without cracking. Blocks were also tested batch by batch during production. At Dhamra, testing followed a QC plan agreed with the client before regular production started, which settled in advance the arguments that usually come later.
Questions to settle before you fix the specification
- What will move and sit on the pavement? Trailers, reach stackers, stored steel. This is your designer's input, and it drives thickness more than anything else.
- Which standard? IS 15658, or BS 6717 if the project calls for it.
- Which shape and laying pattern? Unipaver or brick shape, and herringbone where traffic turns and brakes.
- Who lays it? When the same organisation makes and lays the block, nobody can blame anyone else if the pavement fails.
- How will it be accepted? Agree the testing frequency up front, and ask whether your supplier will put a roller on the finished pavement.
- Where will the blocks be made? For lakhs of blocks at a remote site, a plant at the site can be the safer supply chain. See on-site vs off-site precast.
If you have a yard, a port or an ICD coming up, send us the BOQ or the drawing. We will tell you what we would make, how we would lay it, and where it should be made. Full product specifications are on our paver blocks page.
Common questions
What grade of paver block is used for container yards?
On the container yards and ICDs we have paved, it was M-50, 100 mm (Balmer Lawrie, Visakhapatnam and nine CONCOR ICDs), and M-55, 120 mm at Jalna Dry Port. The right grade for your yard comes from your pavement design and specification.
Is an 80 mm paver block enough for heavy traffic?
At Dhamra Port, 80 mm M-50 unipavers to BS 6717 were specified for internal roads, truck parking and the steel stackyard, and the finished pavement passed the vibratory roller test without cracking. Whether 80 mm suits your area depends on the loads and the base design.
What is the highest paver grade you manufacture?
We manufacture interlocking paver blocks to IS 15658 in grades up to M-55, in thicknesses from 60 to 120 mm, and to BS 6717 where a project specifies it.
Can a damaged paver pavement be repaired instead of replaced?
Yes. The blocks are lifted, the base is put right and the pavement is re-laid. We did this over 12,000 sqm at New Mangalore Port in 2024. See paver pavement repair.
Can the paver blocks be manufactured at our project site?
Yes. The pavements at Dhamra Port, Jalna Dry Port and Balmer Lawrie Container Depot were all made at site, with the plant set up close to the areas being paved.