Cement types — key performance of Portland pozzolana cement (PPC) Which of the following characteristics are associated with PPC compared to ordinary Portland cement (OPC)?

Introduction / Context:
Portland pozzolana cement (PPC) incorporates pozzolanic materials such as fly ash or calcined clay. Understanding its performance aids selection for durability, mass concreting, and sustainability targets.

Given Data / Assumptions:

• Pozzolanic reaction consumes calcium hydroxide, forming additional C–S–H type gels.
• Comparison is with standard OPC of similar grade.
• Long-term properties and heat evolution are considered.

Concept / Approach:
PPC typically shows lower heat of hydration, improving thermal performance in large pours. The pozzolanic reaction densifies the matrix, improving chemical resistance (notably to sulphates) and reducing permeability, which supports water tightness and reduces drying shrinkage tendencies.

Step-by-Step Solution:
Relate pozzolanic consumption of portlandite to improved chemical durability.Link reduced early heat release to lower temperature gradients.Recognize densified microstructure → lower permeability → improved water tightness and shrinkage control.

Verification / Alternative check:
Standards and technical datasheets list PPC for marine, sewage, and mass concrete due to these exact properties.

Why Other Options Are Wrong:
Each single statement is correct; the comprehensive choice best reflects PPC advantages.

Common Pitfalls:
Expecting very high early strength; PPC often gains strength more slowly than OPC but surpasses at later ages.

Final Answer:
All of the above