Silica brick bonding: using a higher percentage of lime as the bond tends to reduce which performance attributes?

Introduction / Context:
Binders and bonds in silica bricks influence microstructure and hot properties. Excess lime can form lower-melting phases, impacting mechanical and wear performance.

Given Data / Assumptions:

• Increasing lime content modifies glassy phases in silica bricks.
• Lower-melting phases decrease hot strength and wear resistance.

Concept / Approach:
While lime is necessary for certain bonding reactions, an overly high fraction promotes fusible phases that weaken the bond at temperature and reduce abrasion resistance. Thus both strength and abrasion resistance decline when lime content is excessive.

Step-by-Step Solution:
Relate lime increase to fusible phase formation.Link fusible phases to reduced hot strength and wear resistance.Select “Both (a) & (b).”

Verification / Alternative check:
Processing notes for silica bricks emphasize controlling bonding agents to maintain high-temperature mechanical performance.

Why Other Options Are Wrong:
Single-attribute reductions are incomplete; both properties suffer.

Common Pitfalls:
Assuming more bond always improves strength; chemistry of the bond matters.

Final Answer:
Both (a) & (b)