Core TradesQuestion 162 of 700
Structural fill placed under a building slab is typically required to be compacted to a MINIMUM relative compaction of about:
a.70%
b.80%
c.90%
d.100%
Explanation
Engineered structural fill is generally compacted to at least 90% relative compaction (based on a laboratory maximum dry density) to limit settlement under the slab; critical areas may require 95%. 70% and 80% are too loose and would allow settling, while a sustained 100% is impractical to achieve uniformly.
Law Reference: 2025 CA Building Code, Chapter 18 (Soils and Foundations)Practice all 700 questions free — no signup required.
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