How does the shape of the aggregate particles affect concrete workability?

The shape of aggregate particles plays a crucial role in determining the workability of concrete. Spherical particles are particularly advantageous because they provide a smoother surface and allow for easier movement and flow within the concrete mix. This rounded shape reduces friction between the particles and helps in achieving better compaction and an overall uniform mix.

With spherical aggregates, the particles tend to roll over one another more smoothly compared to angular or flat particles, which can interlock and create resistance to movement. This interlocking effect in angular-shaped aggregates can lead to a stiffer mix that is more difficult to work with, while flat particles can create gaps and hinder the cohesion of the mixture. Thus, spherical particles enhance the fluidity and workability of concrete, making it easier to place and finish.