Pre-stressed concrete piles — key advantages in handling, durability, and load capacity Which statement best summarizes the practical benefits of using pre-stressed concrete piles for foundations and marine works?

Introduction / Context:
Pre-stressed concrete (PSC) piles are widely used in bridges, jetties, and building foundations. Precompression improves service performance, while factory-controlled production ensures quality and durability. This question tests your understanding of the combined advantages that make PSC piles popular in practice.

Given Data / Assumptions:

• Factory-cast pre-tensioned or post-tensioned concrete piles.
• Appropriate concrete cover, mix, and prestressing level.
• Design considers handling, driving, and in-service loads.

Concept / Approach:

Prestressing introduces a compressive force that offsets tensile stresses from bending during lifting, driving, and service. This minimizes cracking, enhancing durability (especially in marine or aggressive environments). With optimized cross-sections and higher material efficiency, PSC piles can deliver high capacities with lower self-weight relative to comparable non-prestressed RC sections.

Step-by-Step Solution:

Verification / Alternative check:

Design guides show superior allowable driving stresses and higher moment capacities for PSC piles compared to mild-steel-reinforced RC piles of similar dimensions.

Why Other Options Are Wrong:

• Options (a)–(d) are each correct; the comprehensive answer is (e).

Common Pitfalls:

• Ignoring handling and driving stresses in strand layout, leading to cracks despite prestress.
• Underestimating corrosion risks in cut-off zones; proper detailing is still required.

Final Answer:

All of the above.