303Topsoil, Sand-Clay, or Chert Construction

303.1General Description

This work includes constructing a base, subbase, or shoulder course using topsoil, sand-clay, or chert, stabilized with aggregate, where required. Construct according to these Specifications and to the lines, grades, and typical cross-sections shown on the plans or established by the Engineer. All of the provisions of Section 300 apply to this Item. 303.1.01 Definitions General Provisions 101 through 150. 303.1.02 Related References

AASHTO T 99 and 191 GDT 21 GDT 59 GDT 67 303.1.03 Submittals General Provisions 101 through 150. 309 309 309 309 309 309 309 309 309

303.2Materials

Ensure that materials meet the requirements of the following Specifications: Material Section Topsoil or Sand-Clay 814.2.01 Stabilizer Aggregates (Type as Specified) 803 Chert 814.2.04 Cutback Asphalt, RC-30, RC-70, RC-250 or MC-30, MC-70, MC-250 821.2.01 Cutback Asphalt Emulsion, CBAE-2 823.2.01 Blotter Material (Sand) 412.3.05.G.3 If an ingredient needs to be added to those naturally present in the roadbed or in any approved source of base, subbase, or shoulder material, obtain it from sources approved by the Engineer. Select sources according to the guidelines of Section 106. 303.2.01 Delivery, Storage, and Handling General Provisions 101 through 150.

303.3Construction Requirements

303.3.01 Personnel General Provisions 101 through 150. 303.3.02 Equipment Provide equipment in satisfactory condition for proper construction. Use any applicable equipment specified in Subsection 412.3.02, Equipment for bituminous prime. 303.3.03 Preparation If creating the base, subbase, or shoulder construction entirely with new materials, prepare the subgrade or subbase as specified in Subsection 300.3.03.C, Preparing the Subgrade or Subsection 300.3.03.D, Preparing the Subbase. Do not place base materials on muddy or frozen subgrade or subbase. 303.3.04 Fabrication General Provisions 101 through 150. 310 310 310 310 310 310 310 310 310

303.3.05 Construction

If the Engineer determines roadbed materials are unsuitable for use, remove and replace them with approved new materials. If the Engineer determines that roadbed materials are satisfactory, mix, shape, and finish them according to the specifications.

Mix and control the materials according to Subsection 300.3.05.B, Mining and Mixing in a Pit. Handle and place materials carefully to prevent fine and coarse materials from separating. If placing only one kind of material on the prepared subgrade or subbase or adding only one kind of material to the roadbed to obtain the required mixture, place the material directly on the prepared roadbed and distribute uniformly. If mixing together materials from more than one outside source, spread them in separate layers to the proper depth. Do this for each separate course, if placing the base in more than one course. If creating topsoil or sand-clay from artificial mixtures, place the proper proportions of the required ingredients on the roadbed and distribute uniformly. Use the following steps to spread, mix, and stabilize a base, subbase, or shoulder course.

Spread material lengthwise up to 2,500 ft. (750 m) on the roadbed. If the material is too wet to mix, place additional material as the Engineer requires. Mix as soon as the moisture content reaches the proper level.

Mix the material by one of the following methods, weather and moisture conditions permitting:

Without disturbing the underlying subgrade or subbase, plow the material to its full depth, then harrow with a disc harrow. Begin plowing both at the edges and the center, alternating back and forth as many times as necessary, to produce a thoroughly pulverized and homogeneous mixture.

A traveling plant mixer may be used instead of the method described above.

After mixing and shaping the base, subbase, or shoulder course, spread stabilizer aggregate, if specified in the Contract or the plans. The quantity of stabilizer material required will be specified in pounds/square yard (kilograms/square meter) of road surface covered. The Department reserves the right to increase, decrease, or eliminate stabilizer material. Spread and mix stabilizer aggregate with either the upper 4 in. (100 mm) or to the full depth of the course, as the Plans indicate. Uniformly incorporate the stabilizer aggregate into the course. Remix and reshape all sections of the course as needed. When using stabilized subgrade as a base course, either permanently or temporarily (for example, as detours), prime according to Section 412. 311 311 311 311 311 311 311 311 311

Use the following steps to compact and finish a base, subbase, or shoulder course.

Ensure that the moisture content is uniformly distributed and within 90 to 120 percent of optimum. The Engineer will determine the percentage within this range that is appropriate for each job.

If the base, subbase, or shoulder course is more than 8 in. (200 mm) thick, compact it in two courses of equal thickness. After placing and mixing the material, roll it until the course is uniformly compacted to 100 percent of the maximum dry density. Complete all courses of any section of construction started in the same day, weather permitting.

1) Compact the surface by rolling, beginning at least 2 ft. (600 mm) outside of its edges. 2) Proceed toward the center until the finished surface is smooth, closely knit, and conforms to the proper line, grade, and cross-section. 3) Correct any defects according to Subsection 300.3.06.B, Repairing Defects.

1) After compacting the first course, shape the surface again to line, grade, and cross-section. 2) Add water as necessary to develop the proper moisture content. 3) Spread and compact the second and any succeeding courses (including stabilizer aggregate, if required) without rolling the first course again. 4) Finish the surface according to the procedure specified for Subsection 303.3.05.C.2.a, Single-Course Construction.

In places inaccessible to the roller, obtain the required compaction with mechanical tampers approved by the Engineer. Apply the same density requirements as stated above.

Maintain the course true to grade and cross- section. Until the course cures to the Engineer’s satisfaction, keep it free from ruts, ridges, and dust caused by traffic. Roll and add water as needed and repair defects as soon as they appear, as specified in Subsection 300.3.06.B, Repairing Defects.

After completing the base, apply Bituminous Prime according to Section 412. If the base is primed before base material classification test results are known, repair and re-prime any resulting defective areas at no additional cost to the Department. 312 312 312 312 312 312 312 312 312

303.3.06 Quality Acceptance

according to GDT 67 or AASHTO T 99, Method D, where applicable.

or GDT 21, where applicable.

by placing a 15 ft. (4.5 m) straightedge perpendicular to the centerline, and also by using one of the following tools: • A template, cut true to the required cross section and set with a spirit level on non-super elevated sections • A system of ordinates, measured from a string line • A surveyor’s level

surface do not exceed 1/2 in. (13 mm) at any point. Rod readings shall not deviate more than 0.04 ft. (13 mm) from the required readings.

Repairing Defects.

where the shoulders will be surfaced.

necessary to determine the average thickness.

determine the deficient area.

of the following methods according to these specifications: • Add additional quantities of the same materials and reconstruct to the required thickness • Leave in place and accept payment for the materials and area (if the course is mixed in place) at ½ the Contract Unit Price for the deficient area.

same material and reconstructing to the required thickness in accordance with these Specifications.

will be made at the Contract Unit Price with no additional cost to the Department for scarification, mixing or compaction.

to correct deficiencies or reconstructing deficient work. 313 313 313 313 313 313 313 313 313

thickness for any mile (kilometer) increment exceeds the allowable 1/2 in. (13 mm) tolerance, the excess quantity in that increment will be deducted from the Contractor’s payments.

(13 mm) tolerance by the surface area of the base, subbase, or shoulder, as applicable.

303.3.07 Contractor Warranty and Maintenance General Provisions 101 through 150.

303.4Measurement

Topsoil, sand-clay, or chert is measured by the cubic yard (meter) loose volume, or by the square yard (meter), as specified in Section 109.

Stabilizer aggregate is measured by the ton (megagram). Its weight is determined by certified truck scales on the

job, or by another certified scale approved in advance by the Engineer.

Bituminous prime is not measured for separate payment.

When clearing and grubbing is eligible for payment under the provisions of Subsection 106.10, Local Materials

Sources, it is measured by the acre (hectare).

When stripping excavation is eligible for payment under the provisions of Section 206 it will be measured using the

average end area method as borrow excavation, including material, by the cubic yard (meter).

Unsuitable materials removed are measured and paid for under the Earthwork Item in the Contract.

Blending and remixing will be measured by the square yard (meter) as measured on the longitudinal surface, and

to the width specified.

303.4.01 Limits

General Provisions 101 through 150. 314314314314314314314314314

303.5Payment

This course will be paid at the Contract Unit Price per cubic yard (meter) or per square yard (meter) as specified

for base, subbase, and shoulders, complete, in place, and accepted.

Payment is full compensation for:

• Preparing the roadbed

• Furnishing materials when specified in the Pay Item

• Loading and unloading

• Scarifying, spreading, plowing and harrowing

• Mixing and blending in the pit, in the plant, and in the roadway

• Rolling and shaping

• Watering, maintaining, hauling, and priming

Stabilizer aggregate will be paid at the Contract Unit Price per ton (megagram) complete, in place, and accepted.

Payment will be full compensation for furnishing materials, loading, hauling, unloading, handling, spreading,

scarifying, mixing, watering, shaping, and maintenance.

Clearing and grubbing eligible for payment under the provisions of Subsection 106.10, Local Material Sources, will

be paid according to Section 202.

Stripping excavation eligible for payment under the provisions of Section 206 will be paid according to the same

section. Payment will be full compensation for the removal of all materials unsuitable for use in the base, subbase,

or shoulder.

Bituminous prime will not be measured for separate payment. Its cost is included in the price bid for base.

Payment will be made under:

Item No. 303 Topsoil, sand-clay, or chert (base, subbase, shoulder)

course, class ___ including material

Per cubic yard (meter) or square yard

(meter)

Item No. 303 Topsoil, sand-clay, or chert (base, subbase, shoulder)

course, class___

Per cubic yard (meter) or square yard

(meter)

Item No. 303 Topsoil, sand-clay, or chert (base and shoulder) course,

class ___ including material

Per cubic yard (meter) or square yard

(meter)

Item No. 303 Topsoil, sand-clay, or chert (base and shoulder) course,

class ___

Per cubic yard (meter) or square yard

(meter)

Item No. 303 Stabilizer aggregate, type___ including material Per ton (megagram)

303.5.01 Adjustments

General Provisions 101 through 150.. 315 315 315 315 315 315 315 315 315