Answer to Question #300895 in Civil and Environmental Engineering for Glady_7

Question

What are the typical deleterious substances in aggregates that affect Portland cement concrete?

Discuss this effects briefly.

Answer 1

Clay lumps, clay balls, vegetable matter or organics, laminated particles, and shale particles are all deleterious substances in aggregates.

The characteristics of Portland cement concrete (PCC) can be affected by these degrading chemicals.

Effect of clay lumps

·        These reduce durability.

·        These increase the wearing nature of PCC.  

·        May increase water requirements.

·        Loss of workability.

Workability and gradation are also affected by shale or laminated particles.

Soft particles degrade and alter mix percentage ratios, as well as workability and durability.

Vegetable particles may break through the cracks in the concrete, causing irritation. These factors contribute to the formation of voids and a reduction in the strength and durability of PCC.