How can the shape and texture of aggregates affect bonding in concrete?

The shape and texture of aggregates play a significant role in the bonding process within concrete. When aggregates have a rough, angular texture, they provide increased mechanical interlock when combined with the cement paste in the concrete mix. This mechanical interlock is crucial for achieving a strong and durable bond between the aggregates and the surrounding matrix.

Rough surfaces create more surface area for the adhesive properties of the cement to act upon, which enhances the overall strength of the concrete. The angularity of the aggregates allows them to fit together more tightly, reducing the likelihood of movement and separation within the hardened concrete.

In contrast, smooth or rounded aggregates do not engage as effectively with the cement paste, leading to a weaker bond. Flat shapes and equally shaped aggregates can also affect stability, but they do not contribute to the essential interlocking that enhances overall performance. Therefore, the characteristic of rough, angular textures is vital for achieving good bonding and structural integrity in concrete.