CSLB C-12 Earthwork and Paving (Trade Exam) — All Questions

Which task is within the C-12 definition as the Board words it?

• a.Installing guard rails and wheel stops on a lot
• b.Fabricating and installing water pipelines
• c.Forming and finishing structural concrete walls
• d.Placing paving and other surfacing materials✓

The definition includes "the mixing, fabricating and placing of paving and any other surfacing materials." Guard rails and vehicle stops appear in the C-32 definition, fabricating and installing pipelines is the C-34 definition (with its own incidental trenching and paving), and forming and finishing concrete is the C-8 definition.CSLB C-12 classification text (16 CCR Div. 8, Art. 3)

A site plan is drawn at 1 inch = 20 feet. A loading apron measures 4-1/2 inches on the sheet. How long is the apron?

• a.90 feet✓
• b.45 feet
• c.9 feet
• d.180 feet

Each inch is 20 feet, so 4.5 × 20 = 90 feet. Forty-five feet is the result at 1 inch = 10 feet, 9 feet shifts the decimal point, and 180 feet uses 40 feet per inch.CSLB C-12 study guide 13E-12 (computation questions)

Which sheet of a paving plan set shows the pavement layers and their thicknesses?

• a.The erosion-control plan
• b.The typical section✓
• c.The utility plan
• d.The traffic-control plan

The typical section shows the pavement structure as layers (surface, base, subbase) with thicknesses and cross slope. The utility plan locates pipes and cables, the traffic-control plan stages lane closures and detours, and the erosion-control plan shows the stormwater measures.Plan-reading practice; Caltrans 2024 Standard Specifications §26-1.03D (layer thickness)

A profile shows a finish grade rising 3.6 feet over 240 feet. What is the grade?

• a.66.7 percent
• b.15 percent
• c.1.5 percent✓
• d.0.015 percent

Grade is rise over run times 100: 3.6 ÷ 240 = 0.015, which is 1.5 percent. Fifteen percent shifts the decimal, 66.7 percent inverts the ratio, and 0.015 percent reports the decimal as if it were already a percent.Plan-reading practice (percent grade)

Before an excavation begins, what does the Cal/OSHA excavation order require about notice to utility owners?

• a.Notice at least 5 calendar days before digging
• b.Notice when the trench is deeper than 5 feet
• c.Notice at least 2 working days before digging✓
• d.Notice within 2 working days after digging begins

The excavator must advise the regional notification center and known owners at least 2 working days before the start of digging, and must have positive responses from the known owner-operators. Notice after digging begins defeats the purpose, 5 calendar days is longer than the stated period, and a depth of 5 feet does not decide whether notice is needed.8 CCR §1541(b)(2)

Excavation is proposed within 10 feet of a high-pressure natural gas pipeline operating above 60 psig. What does the order require?

• a.Digging at night while the line pressure is reduced
• b.Machine potholing at the line, which is accepted as verification
• c.A repeat of the 2-working-day notice sent to the pipeline owner
• d.An on-site meeting with the owner-operator to verify the location✓

A pipeline above 60 psig is a high priority installation, so an on-site meeting with the owner-operator is required to determine the action needed to verify its location. Repeating the 2-working-day notice is not a substitute for the meeting, digging at night while the pressure is lowered is not a rule in the order, and machine potholing is not the verification method the order describes.8 CCR §1541(b)(1)(B)

A crew will work a loader near an energized 20,000-volt overhead line. What is the general minimum clearance for equipment and the body of an employee?

• a.10 feet
• b.6 feet✓
• c.16 feet
• d.20 feet

For voltages from 600 up to 50,000, the general clearance is 6 feet. Ten feet applies to boom-type equipment and storage in that band (and to the general table above 50,000 volts), 16 feet is for lines above 345,000 volts, and 20 feet is for lines above 750,000 volts.8 CCR §2946, Table 1

A plumber must go down into a 6-foot-deep trench to set pipe. What does Cal/OSHA require of the employer before the trench is dug?

• a.A permit, annual or project-specific, before digging✓
• b.A permit if the trench is wider than 15 feet
• c.A permit for emergency repairs
• d.A permit requested after the trench has been inspected

Trenches or excavations 5 feet or deeper into which a person is required to descend need an annual or project permit. Twenty feet is the engineer-design threshold for sloping, not a permit threshold, so being under it gives no exemption; a 15-foot width does not decide the permit; emergency repair of underground facilities is an exception rather than the trigger; and a permit requested after inspection comes too late because the permit is needed before the trench is dug.8 CCR §341(d)(5), §341(e)

A road base is 900 feet long, 20 feet wide and 6 inches thick after compaction. The base weighs 1.7 tons per cubic yard. About how many tons are needed?

• a.1,134 tons
• b.567 tons✓
• c.333 tons
• d.6,800 tons

The volume is 900 × 20 × 0.5 = 9,000 cubic feet = 333.3 cubic yards, and 333.3 × 1.7 = 567 tons. The 333-ton figure stops at cubic yards, 1,134 doubles the depth, and 6,800 uses 6 feet for the thickness instead of 0.5 foot.CSLB C-12 study guide 13E-12 (computation questions)

A 1,800 bank cubic yard excavation swells 30%. Trucks haul 13 loose cubic yards per load. How many loads are needed?

• a.180 loads✓
• b.234 loads
• c.2,340 loads
• d.139 loads

Loose volume is 1,800 × 1.30 = 2,340 loose yards, and 2,340 ÷ 13 = 180 loads. The 139 loads forgets swell, 234 divides by 10 instead of the truck size, and 2,340 is the loose volume rather than the number of loads.Estimating practice (swell factor)

An embankment needs 6,000 compacted cubic yards. The borrow compacts to 0.80 compacted cubic yard for each bank cubic yard. How many bank cubic yards must be dug?

• a.6,000
• b.7,500✓
• c.4,800
• d.7,800

Bank yards needed = 6,000 ÷ 0.80 = 7,500. Multiplying by 0.80 gives 4,800 and gets the direction wrong, 6,000 ignores the shrinkage, and 7,800 has no basis in the factor.Estimating practice (shrinkage factor)

A parking area of 25,000 square feet is paved with a compacted 0.20-foot course of hot mix weighing 145 pounds per cubic foot. How many tons of mix?

• a.181.3 tons
• b.36.25 tons
• c.362.5 tons✓
• d.725.0 tons

Volume = 25,000 × 0.20 = 5,000 cubic feet; weight = 5,000 × 145 = 725,000 pounds; tons = 725,000 ÷ 2,000 = 362.5. Dividing by 1,000 gives 725, halving the thickness gives 181, and shifting the decimal gives 36.3.Estimating practice (tons from area, thickness and unit weight)

A 6,000-square-yard planed pavement receives tack coat at a minimum residual rate of 0.05 gallon per square yard. How many gallons of residual asphalt are required?

• a.300 gallons✓
• b.600 gallons
• c.120 gallons
• d.180 gallons

6,000 × 0.05 = 300 gallons of residual asphalt. The 120 and 180 gallon figures use the rates for new hot mix (0.02) and for existing asphalt or concrete (0.03), and 600 gallons doubles the correct result.Caltrans 2024 Standard Specifications §39-2.01C(3)(f)

A job costs $150,000 and the estimator adds a 20 percent markup on cost. What is the profit margin on the selling price?

• a.80.0 percent
• b.20.0 percent
• c.16.7 percent✓
• d.25.0 percent

The price is $150,000 × 1.20 = $180,000 and the profit is $30,000, so the margin is 30,000 ÷ 180,000 = 16.7 percent. Twenty percent is the markup on cost, 25 percent inverts the relation, and 80 percent is the cost share of the price.Estimating practice (markup versus margin)

A level is read at 3.18 feet on a benchmark of elevation 212.50 feet. What is the height of instrument?

• a.215.50 feet
• b.215.68 feet✓
• c.3.18 feet
• d.209.32 feet

HI = benchmark elevation + backsight = 212.50 + 3.18 = 215.68 feet. Subtracting the backsight gives 209.32, 3.18 is only the rod reading, and 215.50 is an arithmetic slip.Surveying practice (leveling)

A road segment runs from STA 22+40 to STA 29+15. How long is it?

• a.775 feet
• b.5,155 feet
• c.675 feet✓
• d.6.75 feet

Subtract station values in feet: 2,915 − 2,240 = 675 feet. A reading of 6.75 treats the stations as if they were hundreds, 775 slips by 100 feet, and 5,155 adds the stations.Surveying practice (stationing)

Existing ground at a stake is 101.45 feet and the finish grade is 100.20 feet. What does the stake read?

• a.Fill 0.25 foot
• b.Cut 1.25 feet✓
• c.Fill 1.25 feet
• d.Cut 2.25 feet

The finish is below the ground, so material is removed: 101.45 − 100.20 = 1.25 feet of cut. Calling it fill reverses the sign, and 2.25 and 0.25 are arithmetic slips.Surveying practice (cut and fill)

Which minimum R-value does the State specification require for Class 2 aggregate base?

• a.35
• b.50
• c.22
• d.78✓

Class 2 aggregate base requires a minimum R-value of 78 for contract compliance. Fifty is the Class 3 minimum, 35 is the minimum durability index, and 22 is the minimum sand equivalent.Caltrans 2024 Standard Specifications §26-1.02B

Under method compaction, which machine is the breakdown roller?

• a.A steel-tired two-axle tandem roller
• b.A vibratory roller of at least 7.5 tons✓
• c.A sheepsfoot roller used on soil subgrade
• d.An oscillating pneumatic-tired roller at least 4 feet wide

The breakdown roller is a vibratory roller designed to compact hot mix, at least 7.5 tons and capable of at least 2,500 vibrations per minute. The pneumatic roller is the intermediate roller, the steel tandem is the finish roller, and a sheepsfoot roller is a soil-compaction drum.Caltrans 2024 Standard Specifications §39-2.01C(2)(c)

Which binder grade does the State specification require for replacing asphalt concrete surfacing?

• a.PG 70-10 or PG 76-22
• b.PG 64-10 or PG 64-16✓
• c.PG 58-16 or PG 64-22
• d.PG 52-34 or PG 58-28

Replacement HMA uses PG 64-10 or PG 64-16 asphalt binder. The other grades are real binder grades but are not the ones this section specifies.Caltrans 2024 Standard Specifications §39-3.02B

A grade stake reads "C 0.8." What does it tell the operator?

• a.The compaction must reach 0.8 of maximum density
• b.The finish grade is 0.8 foot below the existing ground at the stake✓
• c.The stake is offset 0.8 foot from the centerline
• d.The finish grade is 0.8 foot above the existing ground at the stake

C stands for cut: the finish is below the existing ground, so 0.8 foot of material is removed. An F stake would show the finish above ground, offsets are written as separate distances, and compaction is not communicated on a grade stake.Surveying and grade-control practice

A 22-foot-wide pavement has a crown at its centerline and a 2 percent cross slope each way. How much lower is each edge than the centerline?

• a.2.2 feet
• b.0.02 foot
• c.0.44 foot
• d.0.22 foot✓

Half the width is 11 feet, and 11 × 0.02 = 0.22 foot. Using the full 22 feet gives 0.44, 0.02 forgets the width, and 2.2 feet shifts the decimal.Grade-control practice (cross slope)

Under the State earthwork specification, how must the grading plane be prepared where hot mix asphalt is to be placed?

• a.No higher than the established grade
• b.Within 0.5 foot above or below the grade
• c.Within 0.05 foot above or below grade✓
• d.Within 0.10 foot below the established grade

Where HMA is placed the grading plane may not vary more than 0.05 foot above or below the established grade. Half a foot is the slope tolerance for excavation slopes, a grading plane no higher than the grade is the rule for concrete base rather than asphalt, and 0.10 foot below grade alone ignores the allowance above grade.Caltrans 2024 Standard Specifications §19-1.03C

How far may the finished aggregate base surface vary from the grade established by the engineer?

• a.Not more than 0.25 foot
• b.Not more than 0.05 foot✓
• c.Not more than 0.01 foot
• d.Not more than 0.5 foot

The finished aggregate base surface must not vary more than 0.05 foot from the established grade. Half a foot is the slope tolerance, 0.01 foot is the curb straightedge tolerance, and a quarter foot is a figure with no basis in the specification.Caltrans 2024 Standard Specifications §26-1.03E

A new curb and gutter is checked with a 10-foot straightedge. How flat must the top and face of the curb and the gutter surface be, except at grade changes or curves?

• a.Within 0.05 foot
• b.Within 0.1 foot
• c.Within 0.02 foot
• d.Within 0.01 foot✓

The curb top and face and the gutter surface must be flat to within 0.01 foot under a 10-foot straightedge. The sidewalk finish tolerance is 0.02 foot, the base tolerance is 0.05 foot, and 0.1 foot is far too loose.Caltrans 2024 Standard Specifications §73-2.03A

The completed surface of a cold-planed pavement is checked with a 12-foot straightedge parallel to the centerline. What is the maximum variation?

• a.0.03 foot of depth plus 0.03 foot of slope
• b.0.05 foot
• c.0.15 foot
• d.0.02 foot✓

The planed surface may not vary more than 0.02 foot under a 12-foot straightedge parallel to the centerline. The 0.05 foot figure is the base tolerance, 0.15 foot is the drop-off limit between open lanes, and 0.03 foot is the allowed depth adjustment and the transverse slope variation, which are not added to the straightedge limit.Caltrans 2024 Standard Specifications §39-3.04C(2)

What cross fall must each embankment layer have while it is being constructed under the State specification?

• a.At least 8 percent
• b.Greater than 10 percent
• c.Level, to give a flat compaction surface
• d.Less than 5 percent✓

Each embankment layer is built with a cross fall of less than 5 percent so that it sheds water without being steep enough to slide. A level layer would hold water, and cross falls of 8 percent or more than 10 percent are steeper than the specified limit.Caltrans 2024 Standard Specifications §19-6.03C

Under the Cal/OSHA soil classification, what is the minimum unconfined compressive strength of Type A soil?

• a.1.5 tons per square foot✓
• b.3.0 tons per square foot
• c.1.0 ton per square foot
• d.0.5 ton per square foot

Type A soil is cohesive soil with an unconfined compressive strength of 1.5 tons per square foot or greater. Half a ton per square foot is the Type C ceiling and the Type B floor, 1.0 ton per square foot is not a class boundary, and 3.0 tons per square foot is not a threshold in the classification.8 CCR §1541.1 Appendix A

How is a clean sand with water seeping from the trench wall classified?

• a.Type B
• b.Stable rock
• c.Type C✓
• d.Type A

Granular soils such as sand are Type C, and submerged soil or soil from which water is freely seeping is also Type C. Type A is cohesive and strong, Type B is intermediate, and sand is not rock.8 CCR §1541.1 Appendix A

Which condition disqualifies a clay from being classified as Type A?

• a.It is moist from a recent light rain
• b.It holds a vertical cut for a few minutes
• c.It is gray and sticky in color and feel
• d.It has been previously disturbed✓

Soil that is fissured, subject to vibration, previously disturbed, in steeply dipping layers or otherwise less stable cannot be Type A. Moisture, holding a cut, color and stickiness are not disqualifiers.8 CCR §1541.1 Appendix A

In the plasticity test, what thread diameter is rolled from a moist sample to see whether the soil is cohesive?

• a.1 inch
• b.1/2 inch
• c.1/8 inch✓
• d.1/32 inch

The sample is molded into a ball and rolled into threads as thin as 1/8 inch; if a 2-inch length can be held on one end without tearing, the soil is cohesive. A 1-inch or 1/2-inch thread is too thick to show cohesion, and 1/32 inch is thinner than the test thread.8 CCR §1541.1 Appendix A(d)(2)

What is the correct formula for relative compaction?

• a.In-place wet density divided by laboratory optimum moisture content
• b.Laboratory maximum density divided by in-place density, times 100
• c.In-place dry density divided by maximum dry density, times 100✓
• d.In-place moisture content divided by dry density

Relative compaction compares the field dry density to the maximum dry density from the laboratory test, expressed as a percentage. Using wet density, moisture content or an inverted ratio does not measure compaction.Caltrans 2024 Standard Specifications §19-5 (relative compaction); California Test 231

A field sample has a wet density of 130 pounds per cubic foot and a moisture content of 8 percent. What is its dry density?

• a.119.6 pounds per cubic foot
• b.140.4 pounds per cubic foot
• c.120.4 pounds per cubic foot✓
• d.130.0 pounds per cubic foot

Dry density = wet density ÷ (1 + moisture content) = 130 ÷ 1.08 = 120.4. Subtracting 8 percent of the wet density gives 119.6, adding 8 percent gives 140.4, and 130 ignores the water.Soil mechanics practice (dry density)

A competent person presses a thumb into a large clump of fresh spoil. The thumb easily penetrates several inches and the soil can be molded by light finger pressure. What does this indicate?

• a.Cohesive soil of about 0.5 ton per square foot or less (Type C)✓
• b.Dry granular soil that crumbles into loose grains
• c.Stable rock that can be cut with vertical sides
• d.Cohesive soil of 1.5 tons per square foot or more (Type A)

Easy thumb penetration of several inches indicates low unconfined compressive strength, about 0.5 ton per square foot or less, which classifies cohesive soil as Type C. Dry granular soil crumbles into loose grains instead of molding into a clump, Type A soil can be indented by the thumb only with very great effort, and stable rock cannot be penetrated.8 CCR §1541.1 Appendix A(d)(2)(C)

At what depth do the Cal/OSHA rules generally require a protective system in an excavation, unless it is in stable rock?

• a.5 feet or more, or any sign of cave-in✓
• b.12 feet or more, unless the soil is Type A
• c.20 feet or more, when an engineer requires it
• d.3 feet or more, or when the soil is Type C

A protective system is required at 5 feet or more, and also in shallower excavations where a competent person finds an indication of a potential cave-in. Three feet is too low a trigger and soil type does not move it, 12 feet is the Type A short-term slope limit, and 20 feet is the engineer-design threshold, so neither starts the protective-system duty.8 CCR §1541.1(a)(1)

What is the maximum allowable slope for an excavation less than 20 feet deep in Type B soil?

• a.1-1/2:1
• b.2:1
• c.3/4:1
• d.1:1✓

Type B soil may be sloped at 1 horizontal to 1 vertical (45 degrees). The 3/4:1 slope is Type A, 1-1/2:1 is Type C, and 2:1 is flatter than required.8 CCR §1541.1 Appendix B, Table B-1

A 6-foot-deep trench in Type C soil with a 3-foot bottom width is sloped at the maximum allowable slope. What is the top width?

• a.15 feet
• b.21 feet✓
• c.12 feet
• d.27 feet

Type C allows 1-1/2:1, so each side runs 6 × 1.5 = 9 feet and the top width is 3 + 9 + 9 = 21 feet. Fifteen feet uses 1:1, 12 feet counts one side only, and 27 feet uses a 2:1 slope.8 CCR §1541.1 Appendix B

In trenches 4 feet or more in depth, how far may an employee have to travel laterally to reach a ladder, stairway or ramp?

• a.No more than 25 feet✓
• b.No more than 100 feet
• c.No more than 10 feet
• d.No more than 50 feet

A means of egress must be located so as to require no more than 25 feet of lateral travel. Fifty feet would be the spacing between ladders (25 feet each way), 100 feet is not a rule, and 10 feet is stricter than the order requires.8 CCR §1541(c)(2)

Excavated soil and equipment must be kept at least how far from the edge of an excavation, unless retaining devices are used?

• a.10 feet
• b.6 inches
• c.2 feet✓
• d.6 feet

Materials and equipment are kept at least 2 feet from the edge or restrained by retaining devices that prevent them from falling or rolling in. Six inches is too close to prevent a fall into the excavation, while 6 and 10 feet are farther than the rule requires.8 CCR §1541(j)(2)

When must the atmosphere in an excavation be tested?

• a.In trenches over 20 feet deep that are in Type C soil
• b.Before entry into an excavation over 2 feet deep, in every soil type
• c.After a worker reports dizziness or illness in the excavation
• d.Before entry over 4 feet deep where a hazardous atmosphere may be expected✓

Testing is required before employees enter excavations greater than 4 feet deep where a hazardous atmosphere or less than 19.5 percent oxygen exists or could reasonably be expected, such as landfill areas. A 2-foot trigger, waiting for illness and a 20-foot Type C rule are not the criteria.8 CCR §1541(g)(1)(A)

When is an employee permitted inside a trench shield?

• a.Not during installation, removal or vertical moves✓
• b.During installation, because the shield protects the worker
• c.While a crane is lifting the shield into position
• d.When the trench is shallower than 8 feet deep

Employees may not be in shields when the shields are being installed, removed or moved vertically, because a suspended or shifting box is itself a hazard. The shield protects workers only once it is set, so installation is the very time to stay out; a crane lift is the same hazard, and a depth limit of 8 feet does not change the rule.8 CCR §1541.1(g)(1)(D)

In what order are members of a trench support system removed?

• a.From the top downward while the trench stays open
• b.In the order that is fastest for the crew
• c.All members at once after the trench is emptied
• d.From the bottom upward, while backfilling✓

Removal begins at and progresses from the bottom, with members released slowly so any sign of failure is noticed, and backfilling progresses together with removal. Top-down or simultaneous removal would leave the lower walls unsupported.8 CCR §1541.1(e)(1)(E), (F)

What is the maximum loose thickness of each embankment layer under the State specification?

• a.4 inches
• b.12 inches
• c.18 inches
• d.8 inches✓

Each embankment layer must not exceed 8 inches loose before compaction, and clods larger than 8 inches must be broken up. Four inches is thinner than needed, and 12 and 18 inches are too thick for compaction energy to reach the bottom.Caltrans 2024 Standard Specifications §19-6.03C

What relative compaction is required in the top 2.5 feet below finished grade under the traveled way and 3 feet each side?

• a.At least 85 percent
• b.At least 90 percent
• c.At least 100 percent
• d.At least 95 percent✓

The State specification requires at least 95 percent relative compaction for 2.5 feet below finished grade for the width of the traveled way plus 3 feet on each side. Ninety percent is the minimum elsewhere in embankment, 85 is below any stated minimum, and 100 percent is not required.Caltrans 2024 Standard Specifications §19-5.03B

In embankment areas that are not required to be compacted to 95 percent, what minimum relative compaction applies?

• a.90 percent✓
• b.85 percent
• c.95 percent
• d.80 percent

Embankment areas not required to reach 95 percent are compacted to at least 90 percent. Eighty-five and 80 percent are below any stated minimum, and 95 is the figure for the critical zones.Caltrans 2024 Standard Specifications §19-5.03C

What is the maximum compacted thickness of any one layer of aggregate base?

• a.0.25 foot
• b.0.50 foot✓
• c.0.67 foot
• d.1.0 foot

The compacted thickness of any one aggregate base layer must not exceed 0.50 foot, and a base thicker than that is built in at least two approximately equal layers. The 0.67-foot limit belongs to structure backfill, 0.25 foot is thinner than the limit requires, and 1.0 foot is thicker than the specification allows.Caltrans 2024 Standard Specifications §26-1.03D

What is the maximum layer thickness for structure backfill before compacting, when compaction is by mechanical equipment?

• a.2 feet
• b.4 feet
• c.0.50 foot
• d.0.67 foot✓

Structure backfill layers may not exceed 0.67 foot (8 inches) before compacting. Four feet is the limit for ponding and jetting, 0.50 foot is the aggregate base limit, and 2 feet is not specified.Caltrans 2024 Standard Specifications §19-3.03E(1)

Backfill may be placed against a cast-in-place concrete retaining wall when the concrete has reached which condition?

• a.When the forms have been stripped and the surface looks hard
• b.At 1,000 psi, even if the wall is a few days old
• c.At least 2,500 psi, or 28 days in place✓
• d.After 7 days in place, if the wall is dry

The specification requires at least 2,500 psi or 28 days in place before backfill is placed against such walls. A hard-looking surface after stripping, 1,000 psi at an early age, and 7 days with a dry wall all fall short of that criterion.Caltrans 2024 Standard Specifications §19-3.03E(1)

In which zone is ponding and jetting of structure backfill not allowed?

• a.The lower 4 feet of the backfill below the footing
• b.Within 50 feet of an abutment wall
• c.The upper 4 feet below finished grade✓
• d.In granular soil near the abutment wall

Ponding and jetting is not allowed in the upper 4 feet below finished grade, and it must be supplemented by vibratory or other compaction equipment. The lower layers may be jetted if the material is self-draining, a 50-foot distance from the wall is not the rule, and soil type alone does not decide the zone.Caltrans 2024 Standard Specifications §19-3.03E(1)

Type A hot mix asphalt with unmodified binder will be placed in a 0.20-foot lift. What are the minimum ambient air and surface temperatures?

• a.65°F air and 80°F surface
• b.45°F air and 50°F surface✓
• c.35°F air and 35°F surface
• d.55°F air and 60°F surface

For lifts of 0.15 foot or more with unmodified binder the minimums are 45°F air and 50°F surface. The 55 and 60 degree values are for thinner lifts, 35 is below any minimum, and 65 and 80 degrees are chip seal conditions.Caltrans 2024 Standard Specifications §39-2.02C