Blog

the difference between normal concrete and self compacting concrete

Concrete is the backbone of a building, but not all concrete works in the same way. For example, there are significant differences between self compacting concrete (SCC) and ordinary concrete in terms of on-site mixing, pouring, and construction methods. Although ordinary concrete has been the most common for decades, self compacting concrete has also had a huge impact on the modern concrete industry by eliminating the need for mechanical compaction.

This guide will provide a clear, side-by-side comparison from the core definition to the final application, helping you understand the difference between normal concrete and self compacting concrete.

Core difference between normal concrete and self compacting concrete

normal concrete (NC)

Normal concrete, also known as “traditional concrete”, is a mixture of cement, aggregates (sand, gravel), water, and sometimes basic additives (such as plasticisers). After pouring, it is necessary to use mechanical vibration (using a vibrating rod or template vibrator) to remove the internal air, compact the mixture, and fill it into each candle of the template.

self compacting concrete (SCC)

self compacting concrete is a high-performance mixture that does not require any external vibration. It can only rely on its own gravity, flowing and filling the template like a viscous liquid, and automatically expelling air during this process, achieving self-compaction.

Performance of self compacting concrete:

High liquidity: easy to spread, no segregation (aggregate sinking or water rising).
Ability to bypass dense steel bars (e.g. 10+bars per square foot) or narrow gaps (as small as 20 millimetres) without clogging.
Stability: Maintain uniformity during placement, without bleeding (separation of water from the mixture) or segregation.

SCC was developed in Japan in the 1980s to address labour shortages and improve the durability of complex structures. Nowadays, it is the preferred choice for high-rise buildings, prefabricated components, and complex building designs.

Other difference between normal concrete and self compacting concrete

1.Mixed design (ingredients and proportions)

Self compacting concrete: Its “secret formula” is “high powder, low material, strong external agent addition”. It utilises finer powder materials (cement, fly ash, slag powder, etc.) and fewer coarse materials (stones), and incorporates a high-performance polyurethane high-efficiency water-reducing agent (PCE). This gives it a liquid-like fluidity, while also being able to ‘grab’ stones and prevent bone loss.
Normal concrete: Its formula is more traditional, aimed at achieving specific strength and a certain degree of plasticity for easy vibration. It cannot achieve high liquidity without losing parsing.

2.Placement process (time, labour, and equipment)

SCC: The process is extremely simplified. After pumping or pouring, workers only need to perform simple surface finishing. This reduces reliance on striking vibration workers and eliminates the loud noise generated by vibration.
NC: Pouring is a labour-intensive process that requires workers to insert heavy vibration rods into the concrete and rely on experience to ensure compaction, which is both labourious and full of uncertainty.

3.Structural durability and quality

SCC: Due to its self-levelling characteristics and self-venting ability, it can form a very smooth, flat, and almost bubble-free surface. This is a huge advantage for concrete projects.
NVC: The final quality is highly dependent on the skills of the workers. Insufficient vibration can leave dangerous honeycombs and holes; Excessive vibration causes surface stones to sink and cement slurry to float (segregate).

4.Applicability

Not every project requires SCC; NC is still an ideal choice for simple, low-complexity work. Here’s how to choose based on your project type:

SCC: It is a powerful tool for solving complex construction problems. It is very suitable for:
Deadly dense structures (such as seismic nodes, high-rise core tubes)
Thin-walled or complex-shaped structures
Difficult to reach areas, such as underground structures or channels, with limited templates (space without vibrators)
Areas with strict noise restrictions.
NC: It is still the most conventional, structurally simple, reliable, and economical choice, such as ordinary foundations, floor slabs, and beams and columns.

5.Cost comparison: unit price vs. comprehensive value

This is a common misconception. Yes, in terms of material unit price, the price of SCC per cubic meter is indeed not as favourable as that of NVC, as it requires more cementitious materials and expensive high-performance additives.

However, the true cost needs to be viewed from the perspective of the entire project:

Save labour costs (consume vibration workers)
Save equipment costs (no need for vibrators)
Weekly schedule (fast pouring speed for divorce)
Reduce decoration costs (with good surface quality)

Taking all these factors into consideration, in many projects, the overall cost of using SCC may be relatively or even equal to that of other methods, while also achieving a higher engineering quality.

Conclusion

The difference between normal concrete and self compacting concrete is like the difference between automatic transmission vehicles and manual transmission vehicles. Both can guide you to your destination, but an automatic transmission provides a more relaxed, smoother, and less reliant driving experience.
normal concrete is a proven industry mainstay, and it is still an economical choice for standard, simple, and efficient application scenarios.

Self compacting concrete coating is a high-performance solution designed to meet the complex, high-quality, and high-efficiency requirements of modern architecture.

By understanding these differences, you can select specific solutions that align with your project goals, saving time, money, and ensuring structural durability.