CSLB Class A — General Engineering (Trade Exam) — All Questions
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15 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
Areas of aggregate base that do not meet the described thickness must be handled how on Caltrans work?
- a.Reported at the end of the contract, in the final estimate
- b.Left alone if the paving crew agrees that the surface will work
- c.Covered with extra pavement to make up the missing depth
- d.Corrected, or a payment deduction requested if paid by volume✓
Areas that do not comply with the described thickness are corrected, or a payment deduction is requested if base is paid for by volume. Not "Left alone if the paving crew agrees that the surface will work": thickness noncompliance must be dealt with. Not "Covered with extra pavement to make up the missing depth": extra pavement does not fix base thickness. Not "Reported at the end of the contract, in the final estimate": correction is required during the work.Caltrans Standard Specifications (2025) 26-1.03E
What is the largest compacted thickness allowed for any one layer of aggregate base?
- a.0.50 foot✓
- b.0.05 foot
- c.1.00 foot
- d.2.00 feet
The compacted thickness of any one layer must not exceed 0.50 foot. Not "1.00 foot": double the stated maximum. Not "0.05 foot": that is the grade tolerance, not the layer limit. Not "2.00 feet": far beyond the stated maximum.Caltrans Standard Specifications (2025) 26-1.03D
On Caltrans work, how much aggregate base does one aggregate gradation and sand equivalent test represent at most?
- a.One truckload of the delivered material on the job
- b.5,000 cubic yards or a week's production, whichever is larger
- c.No more than 500 cubic yards or 1 day's production, whichever is smaller✓
- d.The entire project quantity of the base, tested one time
Each gradation and sand equivalent test represents no more than 500 cubic yards of base or 1 day's production, whichever is smaller. Not "The entire project quantity of the base, tested one time": a single test would not control a long job. Not "5,000 cubic yards or a week's production, whichever is larger": the limits are smaller and the lesser applies. Not "One truckload of the delivered material on the job": the stated limit is far larger than one load.Caltrans Standard Specifications (2025) 26-1.01D(3)
How closely must the finished aggregate base surface match the engineer's grade?
- a.Within 0.25 foot
- b.Within 0.5 foot
- c.Within 0.05 foot✓
- d.To the exact 0.00 foot
The finished AB surface must not vary more than 0.05 foot from the established grade. Not "Within 0.5 foot": ten times looser than the stated tolerance. Not "Within 0.25 foot": far looser than the tolerance. Not "To the exact 0.00 foot": the specification allows a tolerance.Caltrans Standard Specifications (2025) 26-1.03E
Edges of geosynthetic material under aggregate base must overlap by how much?
- a.They are butted with no overlap
- b.At least 2 inches
- c.At least 2 feet✓
- d.At least 20 feet
Adjacent edges of geosynthetic material are overlapped at least 2 feet. Not "At least 2 inches": too small to keep the sheets joined. Not "At least 20 feet": far greater than needed. Not "They are butted with no overlap": the specification requires an overlap.Caltrans Standard Specifications (2025) 26-1.03C
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May equipment be driven directly on filter fabric placed under aggregate base?
- a.Yes, if they travel under 10 mph and avoid sharp turns
- b.No, vehicles may run only on base that has been placed over the fabric✓
- c.Yes, if a thin layer of sand covers the fabric first
- d.Yes, if the vehicles have rubber tires and light loads
The specification says not to operate equipment or vehicles directly on filter fabric. Not "Yes, if the vehicles have rubber tires and light loads": the rubber-tire allowance applies to geogrid, not fabric. Not "Yes, if they travel under 10 mph and avoid sharp turns": the speed allowance applies to geogrid. Not "Yes, if a thin layer of sand covers the fabric first": fabric may be driven on only after base covers it, not by direct operation.Caltrans Standard Specifications (2025) 26-1.03C
Under what condition may vehicles operate directly on geogrid placed under aggregate base?
- a.Yes, since geogrid is much stronger than filter fabric
- b.If the geogrid has been wet for 72 hours and the subgrade is firm
- c.If they have rubber tires, run under 10 mph and avoid sudden braking and sharp turns✓
- d.If they have steel tracks and run fast to avoid sinking into the base
Equipment may operate directly on geogrid only if rubber-tired, under 10 mph and avoiding sudden braking and sharp turns, or once 0.35 foot of base is compacted on it. Not "If they have steel tracks and run fast to avoid sinking into the base": these conditions are not allowed. Not "If the geogrid has been wet for 72 hours and the subgrade is firm": wetness is not a condition. Not "Yes, since geogrid is much stronger than filter fabric": direct operation is restricted.Caltrans Standard Specifications (2025) 26-1.03C
On Caltrans work paid by volume, how is aggregate base placed to fill low areas of the subgrade handled in payment?
- a.It is paid if the engineer is absent when it is placed
- b.It is not included in the payment quantity✓
- c.It is paid as imported borrow at the borrow unit price
- d.It is paid at double the unit price for the extra work
The payment quantity does not include aggregate base used to fill low areas of the subgrade. Not "It is paid at double the unit price for the extra work": the specification excludes it from payment. Not "It is paid as imported borrow at the borrow unit price": base used to fill low areas is not measured or paid as imported borrow. Not "It is paid if the engineer is absent when it is placed": payment does not depend on supervision.Caltrans Standard Specifications (2025) 26-1.04
Aggregate base over biaxial geogrid is being compacted. Which compaction method does Caltrans allow?
- a.A vibratory plate compactor on each lift
- b.No compaction until the base cures in place for a full week
- c.A smooth-wheeled or rubber-tired roller, with no vibratory devices✓
- d.A vibratory sheepsfoot roller set at low amplitude
If biaxial geogrid is shown, base is compacted with a smooth-wheeled or rubber-tired roller and vibratory devices are not used. Not "A vibratory sheepsfoot roller set at low amplitude": vibratory devices are not allowed over geogrid. Not "A vibratory plate compactor on each lift": vibration may displace the geogrid. Not "No compaction until the base cures in place for a full week": base is compacted in layers as placed.Caltrans Standard Specifications (2025) 26-1.03E
How much geosynthetic material may be placed ahead of the base under Caltrans section 26-1.03C?
- a.As much as one roll holds, with no limit
- b.No material until the base is complete
- c.A whole month of material
- d.No more than can be covered in 72 hours✓
The contractor may not place more geosynthetic material than can be covered in 72 hours. Not "A whole month of material": exposed material is damaged by weather and traffic. Not "No material until the base is complete": placement precedes base placement. Not "As much as one roll holds, with no limit": a 72-hour limit applies.Caltrans Standard Specifications (2025) 26-1.03C