Fundamental concepts
Block paving
A small-element pavement built with precast concrete paving blocks. In everyday speech the term is used for almost any concrete-block surface, but in the strict technical sense it means a pavement built with concrete paving blocks conforming to UNE-EN 1338.
Concrete pavers
Precast concrete units, grey or coloured, for external pavements. The market offers many commercial formats and finishes, but in technical documentation the correct term is "concrete paving block" or "small-element pavement", always with reference to the relevant product standard.
Small-element surfacing
An umbrella term: the construction of pavements with concrete blocks, flags, natural stone, artificial stone, clay pavers or, where appropriate, grass grid units. It is a broader category than block paving in the strict sense.
Paving sub-structure
The set of structural layers that spreads the loads beneath the blocks: subgrade (ground + formation level) → geotextile or geogrid where needed → improvement or drainage layer → crushed-stone sub-base or stabilised granular base → fine bedding layer → paving blocks → joint filling.
Block paving as a pavement structure – the system view
A block pavement is not a single layer but a layered pavement structure working as a system, made up of:
- Subgrade (natural ground + formation level)
- Improvement or drainage layer (where needed)
- Load-spreading sub-base (crushed stone / stabilised base)
- Bedding layer (fine grit)
- Block paving surface
- Joint filling
- Edge restraint (kerb)
The structure behaves as a whole: failures can never be attributed to the blocks alone. If the pavers sink, the cause is almost always in the layers beneath – not in the block itself.
Practical rule: 70–80% of defects come not from the paver but from a poor subgrade, an under-designed base, a waterlogged structure or weak edge restraints.
Typical applications
| Area | Recommended surfacing | Notes |
|---|---|---|
| Footpath, garden, patio | 4–6 cm blocks/flags | Light loading; aesthetics and drainage matter most |
| Car driveway | 6 cm, preferably 8 cm blocks | A good sub-base matters more than block thickness alone |
| Car park | 8 cm blocks | Circulation lanes need a stronger base |
| Lorries, industrial yard | 10–12 cm industrial blocks or asphalt/concrete | High shear and wheel loads; edge restraint is critical |
| Public road, bus bay, loading area | Asphalt, concrete or engineered block paving | Requires specific design |
| Town square, urban public space | Natural stone / concrete units | Aesthetics, accessibility, repairability |
When pavers, when asphalt, when concrete?
Block paving is the right choice when:
- traffic is low to medium speed,
- aesthetics are important,
- utility trenches are likely in the future (removable and relayable),
- a modular, repairable surface is needed,
- a permeable system is an advantage.
Asphalt is the right choice when:
- there is continuous vehicle traffic,
- fast construction is required,
- a large continuous area is being built,
- low noise levels matter.
A concrete pavement is the right choice when:
- axle loads are very high (industry/logistics),
- vehicles are slow and heavy,
- static loads and loading operations dominate.
| Criterion | Pavers | Asphalt | Concrete |
|---|---|---|---|
| Aesthetics | Very good | Average | Average |
| Repairability | Excellent, removable | Good, but patchy | Harder |
| Utility access | Excellent | Average | Poor to average |
| Heavy loads | Good if designed for it | Very good | Excellent |
| Construction speed | Average | Fast | Slower |
| Noise | Average | Good | Average |
| Maintenance | Joints, settlement | Cracks, potholes | Joints, cracking |
Summary
A block pavement can perform for decades if:
- the drainage is properly designed,
- the sub-base has the right thickness and is well compacted,
- the edge restraint is stable,
- the block thickness matches the loading.
If any of these is missing, defects can appear within as little as 1–2 years.