CSLB Class A — General Engineering (Trade Exam) — All Questions

What is the "grading plane"?

• a.Surface under the lowest layer✓
• b.The finished pavement surface
• c.The bottom of the deepest utility
• d.The top of the aggregate base

Caltrans defines the grading plane as the basement material surface on which the lowest layer of subbase, base or pavement is placed.Caltrans Standard Specifications (2025) definitions

Which maximum aggregate sizes does Caltrans aggregate base use?

• a.6 inches
• b.1-1/2 inch or 3/4 inch✓
• c.1/4 inch only
• d.3 inches or 2 inches

Caltrans uses either a 1-1/2-inch or 3/4-inch maximum aggregate gradation unless otherwise specified.Caltrans Standard Specifications (2025) 26-1.02

Aggregate base shown 0.90 foot thick is placed in two equal layers. How thick is each compacted layer?

• a.0.30 foot
• b.0.60 foot
• c.0.90 foot
• d.0.45 foot✓

More than 0.50 foot is placed in at least two approximately equal layers, none over 0.50 foot: 0.90 ÷ 2 = 0.45 foot.Caltrans Standard Specifications (2025) 26-1.03

Geosynthetic material under aggregate base is damaged. How is it repaired?

• a.Leave it and add more base
• b.A new piece with 6 inches of overlap
• c.Tape over the tear
• d.A patch with 3 feet of overlap✓

Damaged geosynthetic is repaired by placing a new piece over the damaged area with at least 3 feet of overlap.Caltrans Standard Specifications (2025) 26-1.03

How soon after the initial application of lime must all mixing be completed?

• a.Within 7 days✓
• b.Within 30 days
• c.Within 36 hours
• d.Within 24 hours

All mixing of lime-stabilized soil is completed within 7 days of the initial application of lime; the 36 hours is the minimum mellowing period.Caltrans Standard Specifications (2025) 24-2.03