CLEARING, EXCAVATION, AND EMBANKMENT
PART 1 - GENERAL
1.01 SECTION INCLUDES
A. Clearing and grubbing; preparation of the site; temporary erosion control.
B. Earth excavation. (See Division 3 - For Trench Excavation)
C. Depositing of embankment material.
D. Subgrade preparation.
E. Compaction.
F. Final filling, grading and erosion control.
G. Soil surface restoration.
1.02 DESCRIPTION OF WORK
A. Removal and disposal of all woody and other herbaceous vegetation, rubbish, unsuitable soils, and other objectionable materials.
B. Preparation of the site.
C. Temporary erosion control.
D. Excavation from existing ground surface to subgrade for pavement.
E. Embankment construction to finish grade.
F. Excavation for borrow, shoulders, slopes, open channel ditches, intersections, approaches, private entrances, or driveways.
G. Removal of culverts, driveway pavements, structures, and other obstructions within limits of project.
H. Removal of unsuitable soils.
I. Subgrade construction and stabilization.
J. Adjustments to approximate grade of manholes and other castings and water stop boxes.
K. Final grading and restoration.
L. Reference is made to the Iowa Department of Transportation Standard Specifications for Highway and Bridge Construction, Series 2001, and all current General Supplemental Specifications and Materials Instructional Memorandum by the term "Iowa DOT Specifications" and/or " Iowa DOT I.M."
1.03 SUBMITTALS
A. Submit under provisions of Division 1.
B. Construction sequencing.
C. Results of Standard Proctor and In-Place Density Tests on compactions, when required.
D. Upon requests the Contractor will provide Material Certifications to the Jurisdictional Engineer.
1.04 SUBSTITUTIONS
A. Use only materials conforming to these specifications unless permitted otherwise by Jurisdictional Engineer.
B. Obtain approval of Jurisdictional Engineer for all substitutions prior to use.
1.05 DELIVERY, STORAGE, AND HANDLING
A. Deliver only materials that fully conform to these specifications, or for which submittals have been provided to Jurisdictional Engineer and approved for use.
B. Store cleared, grubbed, and excavated material in locations that will not interfere with operations, minimize environmental damage, and protect adjacent areas from runoff. Provide erosion control around stockpiles.
C. Remove unsuitable and excess materials from the site.
1.06 SCHEDULING AND CONFLICTS
A. Construction Sequence:
1. Attend a preconstruction meeting if required by Jurisdictional Engineer.
2. Submit plan for construction sequence and schedule prior to commencing construction.
B. Conflict Avoidance:
1. Expose possible conflicts in advance of construction, such as utility lines and drainage structures. Verify elevations and locations of each and verify clearance for proposed construction.
2. Complete other elements of the work which can affect line and grade in advance of other open cut construction unless noted on plans.
3. Notify Jurisdictional Engineer of conflicts discovered or changes needed to accommodate unknown or changed conditions.
1.07 SPECIAL REQUIREMENTS
A. Stop Work : Stop work and notify Jurisdictional Engineer immediately if contaminated soils, historical artifacts, or other environmental or historic items are encountered.
B. Use of Explosives: Submit detailed plans outlining all proposed blasting operations, locations, methods, and use of mats and other safety measures to Jurisdictional Engineer.
1. Contractor shall submit detailed plans outlining all proposed blasting operations.
2. Obtain written approval from Jurisdictional Engineer before using explosives.
3. Use thoroughly experienced demolition personnel.
C. Conform to Local, State, and Federal requirements.
D. Classification of Excavation: All project site and borrow excavation will be classified as Class 10, Class 12, or Class 13 hereinafter defined and as indicated in the contract documents.
1. Class 10 Excavation:
a. Class 10 excavation shall include all normal earth materials such as loam, silt, gumbo, peat, clay, soft shale, sand, and gravel. It shall include fragmentary rock handled in the manner normal to this class of excavation.
b. It shall include any combination of the above described materials and any other material not classified as Class 12 or Class 13.
2. Class 12 Excavation:
a. Class 12 excavation shall include the actual measured volume of granite, trap, quartzite, chert, limestone, sandstone, hard shale, or slate in natural ledges or displaced masses.
b. It shall also include the estimated or measured volume of rock fragments or boulders which occur on the surface or in subsurface deposits mixed with earth, sand, or gravel when their size, number, or location prevents them from being handled in a manner normal to Class 10 excavation.
3. Class 13 Excavation:
a. Class 13 excavation shall include all materials included under the definitions of Classes 10 and 12 and any other material encountered, regardless of its nature.
b. The various materials encountered in Class 13 excavation shall be used or removed as provided for the various kinds of material.
c. No separate measurements of such various classes of materials will be made. This classification covers work commonly referred to as "Unclassified Excavation".
d. The contract documents will specify the limits for Class 13 excavation. Excavation within these limits shall not be classified as Class 10 or Class 12 excavation.
E. Borrow: Unless otherwise provided in the contract documents, when the quantity of material required for embankments is not available within the limits of the project cross sections or specific borrow areas as indicated, the Contractor shall make up the deficiency from borrow areas provided by the Engineer or furnish equivalent material from alternate borrow areas.
1. Mandatory Borrow Area:
a. An area provided by the Contracting Authority from which the Contractor is expected to obtain borrow material and to operate in the area in accordance with the contract documents.
b. Mandatory borrow areas will be designated in the contract documents.
c. Where a mandatory borrow area is designated in the contract documents, it is mandatory that borrow material be obtained from the borrow location designated unless permission is obtained from the Jurisdictional Engineer to obtain borrow from another location.
2. Optional Borrow Area:
a. An area provided by the Contracting Authority from which the Contractor may obtain borrow material.
b. If so obtained, the Contractor is expected to operate in the area in accordance with the contract documents.
c. Borrow areas are optional borrow areas unless specifically designated as mandatory borrow areas.
3. Alternate Borrow Area:
a. An area outside the project right-of-way provided or to be provided by the Contractor from which the Contractor may obtain borrow material.
b. Use shall be in accordance with the contract documents.
c. The Contractor is responsible for obtaining all rights associated with this area and for use of this material.
F. Placement of Fill Material in Streams and Water Bodies:
1. The placement of fill material in streams is regulated by Federal law, State law, and local ordinances. The intent of this specification is to require contractor operations in streams and other water bodies and adjacent swamps, marshes, bogs, or similar areas to be in compliance with Federal and State regulations.
2. Fill material means any material used for the primary purpose of replacing an aquatic area with dry land or of changing the bottom elevation of a water body.
3. Fill material shall consist of clean, suitable, naturally occurring material, which is free from unacceptable levels of toxic pollutants.
4. Temporary stream crossings shall be bridged or culverted to not restrict expected high flows or disrupt the movement of aquatic life native to the stream or water body. They shall not extend over 100 feet into any swamp, bog, marsh, or similar area that is adjacent to the stream or water body. Expected high flows are those flows which the Contractor expects to experience during the period of time that the crossing is in place.
5. Temporary stream crossings shall be maintained to prevent unnecessary erosion and other non-point sources of pollution. Temporary crossings shall be removed after they are no longer needed.
G. Abandoned Utilities: When required for construction of new sewer pipes, existing and abandoned storm sewer and sanitary sewer lines shall be removed. Removal of all other utility lines shall be the responsibility of the respective utility agency and shall not be measured for payment. The Contractor at his option may elect to fill existing or abandoned storm sewer and sanitary sewer lines with flowable fill.
1.08 MEASUREMENT FOR PAYMENT
All measurements for payments will be made by the Jurisdictional Engineer or authorized representative.
A. Clearing and Grubbing (By units):
Payment for Clearing and Grubbing including, removal of trees, stumps, logs and down timber, hedge rows, brush, field fence, and agricultural products shall be made at the contract unit price. The units will be per acre for Grubbing including all down timber, and trees/stumps less than or equal to 6 inches in diameter, by Clearing per tree size removed for trees greater than 6 inches in diameter and by grubbing per stump size removed for existing standing stumps of previous cut trees.
1. Grubbing by Acre:
All standing trees, stumps, and down trees 6 inches or below in diameter measured 18 inches above the root system. Measurement units to be in acres measured by the Jurisdictional Engineer unless indicated incidental in the contract documents. Include costs in the price bid for:
a. Cutting, removing, and disposal of trees and stumps, including roots.
b. Removal and disposal of logs and down timber.
c. Pulling or grubbing and disposal of hedges, bushes, and shrubs, including roots, agricultural products, and designated field fence.
d. Removal and disposal of all vegetation and rubbish.
e. Other objectionable and miscellaneous materials as indicated on the Plans.
2. Clearing by Tree Size:
Tree removal greater than 6 inches diameter. If indicated in the contract documents, trees larger than 6 inches, 18 inches above the ground, will be measured for payment. Measurement shall be in diameter inch of tree removed:
a. Cutting, removing, and disposal of trees, including roots.
b. Jurisdictional Engineer shall measure the circumference before removal of each tree to the nearest inch, 18 inches above normal ground elevation. Diameter to be determined by dividing the circumference by 3.14.
c. Each tree to be removed to be marked with size by the Jurisdictional Engineer.
d. Removal by Contractor to be considered as acceptance of the tree size so marked by the Jurisdictional Engineer and only trees marked by the Jurisdictional Engineer shall be removed.
3. Grubbing by Existing Stump Size:
Stump removal greater than 6 inches diameter. If indicated in the contract documents, stumps larger than 6 inches of previously cut trees (not cut under Section 2010, 1.08 A.2) will be measured for payment.
a. Includes removing existing stumps and roots and disposal.
b. Stumps greater than 6 inches in diameter will be measured for payment. Measurement shall be in diameter inch of stump removed.
c. Jurisdictional Engineer shall measure the diameter to nearest inch at the cut line.
d. Each stump to be removed to be marked with size by the Jurisdictional Engineer.
e. Removal by Contractor to be considered as acceptance of size.
B. Combined Clearing and Grubbing (By Acre):
Combined Clearing and Grubbing shall be bid per acre and shall include all combined clearing, grubbing, tree and stump removal as specified in Section 2010, 1.08, A, 1, 2, and 3. The Jurisdictional Engineer shall not measure any tree or stump under this item.
C. On-Site Topsoil:
1. Measurement will be in cubic yards of topsoil stripped, salvaged, and spread and will be computed on the basis of a uniform 8-inch finished thickness, or as specified. Payment will be at the unit price.
2. Topsoil salvaged from excavated areas and paid for as topsoil will not be included in excavation quantities for which payment is made.
3. Overhaul will not be paid.
D. Compost-Amended Topsoil: Measurement and payment will be as for on-site topsoil (see Section 2010, 1.08, C) and furnishing and incorporating compost.
E. Off-Site Topsoil: Measurement and payment will be at the contract unit price per cubic yard for furnishing, excavating, hauling, and incorporating the material.
F. Class 10 or Class 13 Excavation:
1. The project site and borrow excavation measurement to be in cubic yards for Class 10 or Class 13 excavation removed between the original surface and the final subgrade.
2. Should the Contractor or the Jurisdictional Engineer desire actual measurements rather than using contract document quantities, written notice shall be given to the other party prior to starting work.
a. If actual measurements are used, cross-section surveys by the Jurisdictional Engineer before and after work shall be the basis of computing the cubic yards of excavation. The extra survey cost will be paid for by the party requesting the survey.
b. On projects that the Jurisdictional Engineer determines it is impractical to make cross-section surveys, the truck count method shall be used with a shrinkage factor resulting in volume per truck type and size determined by the Jurisdictional Engineer. Unless stated otherwise in the contract documents, a shrinkage factor of 1.30 shall be used for Class 10 and Class 13 excavation.
c. The Contract documents may provide for payment of earthwork by plan quantity without final field measurement. Adjustments may be made to the plan quantities when agreed to by the Jurisdictional Engineer and Contractor when obvious errors or authorized changes occur.
3. Include costs in the price bid per cubic yard for:
a. Preparation of the site for embankment and the formation and the construction of embankment, fills, shoulder backfill, and backfill behind curbs.
b. The stripping, salvaging, and spreading of 8 inches of topsoil unless otherwise provided in the contract documents.
c. The finishing of the earth surface, including roadways, shoulders, behind curbs, side ditches, slopes, and borrow pits.
d. The repair and replacing of all fences that have been unnecessarily damaged or removed.
e. Compaction testing to be included in the costs of the prices bid if required in the contract documents.
f. Payment shall not be made for excavation work done prior to the staking and, if necessary, cross-sectioning.
G. Alternate to Class 10 Excavation
1. Embankment in Place: Measurement to be in cubic yards of embankment determined by the Jurisdictional Engineer using cross section and average end area. The quantity for which payment is made shall not exceed the constructed embankment, adjusted for settlement. Include cost in price bid per cubic yards as in Section 2010, 1.08, F, 3.
2. Earthwork, Lump Sum
a. Earthwork, Lump Sum will be paid for at the contract lump sum price bid. The price bid shall be full compensation for all earthwork required to construct the project to the grade and elevation shown on the plans including Class 10 Excavation; Stripping, Salvaging and Spreading Topsoil; borrow; and hauling and compaction.
b. Class 12 excavation shall be bid separately and shall not be included as part of Earthwork, Lump Sum.
c. Any earthwork quantities shown in the plans are for estimating purposes only. The Contractor is responsible to check the estimated earthwork quantity. If the contractor does not agree with the plan quantity prior to bidding, the contractor may contact the Jurisdictional Engineer to request an addendum to the contract document. Regardless if the addendum is issued or not issued the successful bidders lump sum price is final.
d. The contractor shall submit a schedule of quantities and unit prices for each type of relevant work associated with the project as described in the plans. The unit prices shall be used to establish the total cost for any extra work orders related to earthwork unless otherwise negotiated.
e. Monthly estimates of the work performed will be made based on the schedule of unit prices and will be used to prepare progress payments to the Contractor.
H. Core Out Excavation: Shall be measured and paid for by the cubic yards removed by field measurement. When the contract documents do not contain a core out excavation bid item, and core out excavation is required by the Jurisdictional Engineer, the following shall be adhered to:
1. Excavation shall be paid for by Change Order unless otherwise provided in the contract documents.
2. Payment for core out excavation shall include equipment, tools, labor, disposal of unsuitable materials, dewatering, drying, compaction and finishing, and all incidental work as may be required to make the grading work complete.
3. Measurement for payment for replacement of unsuitable or unstable soils with select soil backfill or treated stabilization material(s) will be in accordance with Sections 2010, 1.08, K or L.
I. Class 12 Rock Excavation: Shall be measured and paid for by the cubic yards removed. When the contract documents do not contain a rock excavation bid item and rock is encountered, the following shall be adhered to:
1. The Jurisdictional Engineer shall verify the rock excavation.
2. Excavation of rock shall be paid for by Change Order unless otherwise provided for in the contract documents.
3. The payment for rock excavation shall include equipment, tools, labor, disposal, and all incidental work necessary to make the grading complete.
J. Structure Removal: Count the numerical quantity of each manhole, storm drain inlet box, and single span bridge removed in accordance with the Plans.
K. Pavement Removal/Disposition: Shall be measured and paid for by the square yards removed. No payment shall be made for pavement removed beyond the limits designated on the Plans or authorized by the Jurisdictional Engineer.
L. Sidewalk/Driveway Removal/Disposition: Shall be measured and paid for by the square yards removed. No payment shall be made for sidewalk removed beyond the limits designated on the Plans or authorized by the Jurisdictional Engineer. For unintentional over-excavation and repair of same, no payment shall be made.
M. Select Soil Backfill Material: Below subgrade backfill in core out sections with select soil includes furnishing, placement, and subgrade preparation, and is measured in cubic yards of volume to be filled; increased by the percentage of shrink shown in the contract documents. When no value is given in the contract documents, a shrinkage factor of 1.15 shall be used to determine the volume of material placed.
N. Treated Stabilization Material Backfill: Below subgrade backfill in core out sections with treated stabilization material(s) includes furnishing, placement, and subgrade preparation, and is measured in cubic yards or tons of volume to be filled. Measurement of material includes water naturally present or added for proper compaction.
O. Subgrade Treatment: Treatment with polymer grid, lime, fly ash, or cement measured and paid in square yards shall include 2 feet outside of pavement for each side. No separate payment will be allowed for subgrade preparation.
P. Subgrade Preparation: Moisture and Density Control shall be measured in square yards shall include 2 feet outside pavement for each side.
Q. Granular Subbase: Subbase shall include furnishing and placement measured in square yards of material placed according to the plans. Includes water naturally present or added for proper compaction.
R. Fixture Adjustment:
New fixtures, constructed and adjusted with the project shall not be measured for payment but shall be considered incidental. Adjustment of existing fixtures shall be paid for as follows:
1. Manhole Adjustment, Minor (manhole ring adjustment only): Refer to Section 6020 for Measurement and Payment of Manhole Adjustment, Minor.
2. Manhole Adjustment, Major (manhole barrel, cone, or flat top adjustments): Refer to Section 6020 for Measurement and Payment of Manhole Adjustment, Major.
3. Adjust traffic handhole to grade: Adjustment is considered an incidental item unless specified in the contract documents. If specified as a pay item it shall be at the unit price for each adjustment. Count the number of traffic handholes adjusted to grade by raising or lowering existing traffic handholes.
4. Adjust valve box to grade, minor (existing adjustable boxes with sufficient adjustment): Adjustment is considered an incidental item unless specified in the contract documents. If specified as a pay item it shall be at the unit price for each adjustment. Count the number of valve boxes adjusted to grade by lowering or extending existing box.
5. Adjust valve box to grade, major (new extensions): Payment shall be at the unit bid price for each major adjustment. Count the number of valve boxes adjusted to grade by addition of new extension or sections to existing valve box.
6. Adjust Fire Hydrant to grade: Adjustment is considered an incidental item unless specified in the contract documents. If specified as a pay item it shall be at the unit price for each adjustment. Count the number of hydrants adjusted to grade by raising or lowering existing hydrants.
7. Patches and all associated work required for adjustment of fixtures in pavement shall be incidental.
S. Locating Tile Lines: For the number of stations trenched and backfilled as described in the contract documents the Contractor will be paid the contract unit price per station.
T. Intercepting Ditches and Flumes: Intercepting ditches and flumes will be measured and paid for in linear feet along their center lines.
U. Compaction Testing: Shall be in accordance with this Section.
1. Contract documents shall indicate whether Jurisdiction or contractor shall be responsible for testing.
2. If contractor is responsible for testing, it shall be performed by an authorized independent testing lab, hired by the contractor, and shall be paid for on a lump sum basis.
3. If Jurisdiction is responsible for testing, the Jurisdiction shall assume costs required, except retesting resulting from failure of the initial tests. Pay request for testing shall indicate whether the test is initial or a retest.
4. In all cases, the contractor shall pay for retesting resulting from failure of initial tests.
V. Dust Control: Dust control shall be measured by the square yard of treated roadway surface. (Blading of loose material from road surface shall be considered incidental to the item.)
W. Removal of Existing Utility Lines and Conduits
1. Known Pipe:
a. When removal of utilities are indicated on the plans, removal shall be measured in linear foot of utility actually removed. Payment shall be at the unit price of applicable size and type of pipe.
b. Pipe will be removed according to the limits shown on the plans and the pipe will be capped upon the Jurisdictional Engineer's approval of construction capping method. Capping will be considered incidental to the removal.
2. Unknown Pipe: Removal of Existing Utility Lines and Conduits within the limits required to complete the work. The contractor will be paid the agreed unit price per linear foot removed with capping to be considered incidental to removal. If the Jurisdictional Engineer approves the filling the utility pipe with flowable mortar in lieu of pipe removal, the contractor will be paid the plan unit price for pipe removal or an agreed unit price.
PART 2 - PRODUCTS
2.01 CLEARING AND GRUBBING
Except for those items which are to be preserved as indicated in the contract documents or as designated by the Jurisdictional Engineer, all woody and other herbaceous vegetation, field fences, trees, brush, stumps, roots, down timber, rubbish, etc. shall be removed from the project area and from borrow pits furnished by the Contracting Authority. Work shall be classified as follows:
A. Clearing: Clearing shall consist of cutting, removal and disposal of trees greater than 6 inches in diameter.
B. Grubbing: Grubbing shall consist of removal and disposal of the following:
1. All stumps, including roots, all trees, and all down timber 6 inches or less in diameter.
2. Hedge removal shall consist of pulling or grubbing of hedge fences of Osage Orange or shrubs planted close together in rows. If any individual tree, of those composing a hedge, has a diameter greater than 6 inches, it shall be measured as clearing unless bid as a clearing and grubbing by acre.
3. Brush removal shall consist of pulling or grubbing of trees and shrubs 6 inches or less in diameter, including roots, which are not classified as hedge.
4. Removal of agricultural products shall consist of cutting stalks to a height of not more than 5 inches above the ground, removal of the stalks, and a thorough disking of the stubble.
5. Vegetation and rubbish removal shall consist of removal of all vegetation and all rubbish encountered.
6. Field fence shall be removed from the project.
2.02 ON-SITE TOPSOIL
Use suitable topsoil of uniform quality, free from hard clods, roots, sods, stiff clay, hard pan, stones larger than 1 inch (1/2 inch for turfgrass seeding), lime cement, ashes, slag, concrete, tar residue, tarred paper, boards, chips, sticks, or any undesirable material.
Use on-site topsoil, unless compost-amended or off-site topsoil is specified.
A. On-Site Topsoil: On-site topsoil material is suitable material excavated from the top 12 inches of the site. Use of on-site topsoil material is subject to the Jurisdictional Engineer's approval.
B. Compost-Amended On-Site Topsoil: Amend low-quality on-site topsoil, not meeting the requirements specified for off-site topsoil, with a minimum of 1 inch of compost for every 3 inches of topsoil. Use compost meeting the requirements of Section 9010, 2.02, C.
C. Off-Site Topsoil: Contains at least 3% organic matter, according to ASTM D, 2974, has a high degree of fertility, is free of herbicides that prohibit plant growth, has a pH level between 6.0 and 8.0, and meets the following mechanical analysis requirements.
* 100% for turfgrass
Sieve Percent Passing 1" 100 1/2" 95* to 97* 1/4" 40 to 60 No. 100 40 to 60 No. 200 10 to 30 The Jurisdictional Engineer will approve the source of off-site topsoil. Surface soils from ditch bottoms, drained ponds, and eroded areas, or soils that are supporting growth of noxious weeds or other undesirable vegetation will not be accepted. The Jurisdictional engineer will determine if testing is necessary. The Contractor will be responsible for payment of the testing if the off-site topsoil does not meet the above requirements. If the testing verifies the off-site topsoil does meet the above requirements, payment for the testing will be the responsibility of the Jurisdiction.
2.03 EXCAVATION MATERIALS
A. Class 10 Excavation: Excavation of all normal excavation and borrow such as loam, silt, gumbo, peat, clay, soft shale, sand, gravel and fragmentary rock.
B. Class 12 Rock Excavation: Material deposits so firmly cemented together that they cannot be removed without continuous use of pneumatic tools or blasting.
C. Class 13 Unclassified Excavation: Excavation of all materials encountered, regardless of nature. The various materials encountered shall be used or removed as provided for the various types of material.
D. Structures: Concrete structures, manholes, and storm drain inlets.
E. Surfacing Materials: Concrete pavement, asphaltic pavement, and sidewalks.
F. Rubbish and Debris: Unsuitable materials such as trees, stumps, waste construction materials, scrap metals, and other materials not suitable for backfilling or for topsoil.
G. Unsuitable or Unstable Materials: Material encountered during excavation above or below grade that does not meet the requirements of Section 2010, 2.04 A Suitable Soil and which cannot be properly placed in the subgrade of cut or fill section. Moisture content shall not determine suitability of materials.
2.04 EMBANKMENT MATERIALS
A. Suitable Soils:
1. All soils provided for the construction of embankments shall meet the following requirements, and shall be suitable when moisture control or moisture and density control are designated.
a. 95 pcf or greater density (ASTM D 698 Standard Proctor Density).
b. AASHTO M145-91 index of less than 30.
c. Soils not meeting these requirements are considered unsuitable soils.
d. Soils to be placed below water shall be clean granular material.
B. Select Soils:
1. All soils required for select subgrade treatments shall be as approved by the Jurisdictional Engineer. Approval of materials and their use will be based on AASHTO M 145-91.
a. Cohesive Soils shall meet all of the following requirements.
1) 45 percent or less silt size fraction.
2) 110 pcf or greater density (ASTM D 698 Standard Proctor Density).
3) Plasticity index greater than 10.
4) A-6 or A-7-6 soils of glacial origin.b. Granular soils shall meet all of the following requirements.
1) 110 pcf or greater density (ASTM D 698 Standard Proctor Density).
2) 15 percent or less silt and clay.
3) Plasticity index, 3 or less.
4) A-1, A-2, or A-3 (0).2. Jurisdictional Engineer may authorize a change in select soils subject to materials available locally at time of construction.
C. Subgrade Treatment:
1. Fly Ash:
a. Meet requirements of ASTM C 618 or AASHTO M 295.
b. Either Class C or Class F. For Class C, the pozzolanic activity test with lime will not be required.
c. Approval of source required.
2. Lime: Hydrated lime shall meet requirements of ASTM C 207, Type N or AASHTO M 216.
3. Geogrid: The geogrid shall be an integrally formed grid structure manufactured of a stress resistant polypropylene material. Use Type 1 geogrid, unless Type 2 is specified. Meet the following minimum physical properties:
Property
Test Method
Units
Type 11
Type 2
Aperture Stability Modulus at 20 cm-kg1
Kinney2 – 01
cm-kg/deg
3.2
6.5
Minimum True Initial Modulus in Use
Machine Direction (MD)
Cross Machine Direction (CMD)ASTM D 6637-01
lb / ft
15,080
20,56032,890
44,725Tensile Strength, 2% Strain
MD
CMDASTM D 6637-01
lb / ft
270
380410
590Junction Efficiency
GRI-GG2-87
%
93
93
Flexural Rigidity
ASTM D 1388-96
mg-cm
250,000
750,000
Aperture Size
Minimum
Maximumin.
in.0.5
2.00.5
2.01 Geogrids meeting the requirements of Iowa DOT Section 4196.01, E and I.M. 496.01 will be acceptable.
2 Dr. Thomas C. Kinney, P.E. and US Army Corps of Engineers.D. Granular Subbase:
1. Class A Subbase (Iowa DOT Special Backfill)
a. Clean, crushed stone or crushed concrete with the following gradation:
Sieve
Percent Passing
1-1/2 inch
100
No. 8
15-45
No. 200
0-10
Iowa DOT Gradation No. 30 (Iowa DOT 4109 and 4132)
b. Jurisdictional Engineer may authorize a change in gradation subject to materials available locally at time of construction.
2. Class B Subbase – Open Graded (Iowa DOT Granular Subbase)
a. Clean, crushed stone or crushed concrete having the following gradation:
Sieve
Percent Passing
1 inch
100
No. 8
10 to 35
No. 50
0 to 15
No. 200
0 to 6
Iowa DOT Gradation No. 12 (Iowa DOT 4109 and 4121)
b. Jurisdictional Engineer may authorize a change in gradation subject to materials available locally at time of construction.
3. Class C Subbase (Reclaimed Asphalt Product - RAP): Salvaged asphalt cement concrete and unclassified reclaimed asphalt cement pavement (Iowa DOT 2303.02) shall be processed so that the material meets Iowa DOT special backfill requirements (Gradation No.30).
4. Class D Subbase (Iowa DOT Modified Subbase)
a. Clean, crushed stone, or crushed concrete with the following gradation:
Sieve
Percent Passing
1-1/2 inch
100
3/4 inch
70 to 90
No. 8
10 to 40
No. 200
3 to 10
b. Jurisdictional Engineer may authorize a change in gradation subject to materials available locally at time of construction.
c. Recycled crushed PCC pavement, crushed composite pavement, and salvaged HMA may be reclaimed from an existing street or roadway. When the source or quality of the recycled material is unknown, the material shall meet the requirements of Iowa DOT Article 4123.01, A. Certified RAP may be used.
E. Stabilization Materials (Section 3010, 2.02):
1. Clean, crushed stone, or crushed concrete, with the following gradation:
Sieve
Percent Passing
2-1/2 inch
100
2 inch
90 to 100
1-1/2 inch
35 to 70
1 inch
0 to
15201/2 inch
0 to 5
2. Jurisdictional Engineer may authorize a change in gradation subject to materials available locally at time of construction.
F. Unsuitable Soils - See Section 2010, 3.06
2.05 COMPACTION EQUIPMENT
A. Sheepsfoot Roller:
1. Sheepsfoot type rollers shall consist of one or more drums having studs or feet projecting not less than 6-1/2 inches from the surface of the drum.
2. The roller shall be loaded so that not less than 200 psi is exerted on a single row of feet parallel to the axle of the drum.
B. Pneumatic Tired Roller:
1. On embankments constructed primarily of sand or other granular material, the Contractor may, substitute a pneumatic tired roller weighing not less than 200 pounds per inch width of roller in lieu of the sheepsfoot type roller.
2. Pneumatic tired rollers shall have tires not smaller than the 7.50 x 15 size.
3. The rollers shall be loaded to produce a compactive effort not less than 200 pounds per inch width of the roller, based on the maximum ground contact width.
4. The tire inflation pressure used shall not be less than 60 psi and shall not vary more than 5 psi.
2.06 DUST CONTROL
A. Calcium Chloride: Meet requirements of Iowa DOT 4194.01.
B. Lignosulfonates (Tree sap): Lignosulfonate 58A. Other commercially available Lignosulfonate products intended for dust control may be allowed upon approval of Jurisdictional Engineer.
PART 3 - EXECUTION
3.01 PREPARATION BY THE CONTRACTOR
A. Verify suitability of excavated materials for reuse as backfill.
B. Locate, mark, and protect existing utilities and facilities in the work area.
C. Provide accessibility to utility service locations, such as valves, manholes, and utility poles.
D. Protect existing facilities, trees, and shrubs to remain in place. Do not disturb trees within 10 feet of the drip line without notifying the Jurisdictional Engineer. The contractor shall mark the 10-foot limit from the drip line.
E. Protect bench marks, control points, and land survey monumentation.
F. Prior to construction identify owners of utilities on or near the site, notify them of operations to occur, and have all utility lines or services located.
1. Location of utility lines, mains, cables, and appurtenance shown on plans are from information provided by utility companies and the Owner.
2. The Contractor is responsible for excavating and exposing underground utilities in line of work. Confirm location of underground utilities by excavating ahead of work.
3. The Contractor is solely responsible for any damage to utilities or private or public property due to utility disruption.
4. The Contractor shall notify Owner and utility agency immediately if utility line is damaged during construction.
5. Support and protect utility lines, poles, and appurtenances in conflict with line and grade of work during construction.
6. Utility services are not generally shown on plans; protect and maintain services during construction.
7. No claims for additional compensation shall be allowed to Contractor for interference or delay caused by utility agency. All utility coordination is the responsibility of the Contractor.
G. Construction Sequence:
1. Prior to site construction operations, Contractor shall submit a proposed construction schedule.
2. Obtain the necessary permits.
3. Install the required traffic control.
4. Remove all items as listed on the plans.
5. Install erosion control.
6. Construct all underground utilities.
7. Construct the project in stages as indicated in the plans.
8. Adjust manholes and other fixtures to new grades.
9.
BackfillPlace backfill, including shoulder areas and behind curbs, as per plans and finish gradeearthsoil surfaces as shown on the plans.10. Install plantings, sodding, and/or seeding.
3.02 CLEARING AND GRUBBING
A. Notification: Notify Jurisdictional Engineer prior to start of clearing and grubbing activities.
B. Removal: Remove the following items:
1. Trees, stumps, including roots.
2. Logs and downed timber.
3. Hedges, bushes, and shrubs, including roots.
4. Vegetation and rubbish.
5. Other objectionable materials.
C. Disposal: Material from clearing and grubbing may be removed in accordance with Iowa Administrative Code 567-23.2 and must meet local ordinances. Material from clearing and grubbing may be processed by such means as chipping of logs, down timber, or brush, for mulching material, or salvaging of logs and down timber for firewood. Other vegetation including corn stubble may be disked into the existing ground surface if approved by the Jurisdictional Engineer. Materials from clearing and grubbing, other than field fence, that is not handled on the project shall be hauled to a “yard waste” landfill. Field fence shall be removed from the project and may be deposited in an appropriate landfill.
D. Miscellaneous Removal:
1. Remove and temporarily reset private mail boxes as necessary.
2. Replace private mail boxes as per Owner and/or U.S. Post Office/Jurisdiction.
3. Notify Jurisdiction when removal of street signs is necessary.
3.03 STRIPPING, SALVAGING AND SPREADING TOPSOIL
A. Stripping and Salvaging Topsoil:
1. Mow all weeds, grass, and growing crops or other herbaceous vegetation close to the ground and remove from the site. Shred sod by shallow plowing or blading and thorough disking. Thoroughly shred to allow the soil to be easily spread in a thin layer over areas to be covered. If allowed by the Jurisdictional Engineer, herbicides may be applied and vegetation may be incorporated into the topsoil.
2. Remove an adequate amount of topsoil from the upper 12 inches of existing on-site topsoil to allow finish grading with a finished 8 inches of salvaged or amended topsoil. The topsoil may be moved directly to an area where it is to be used or may be stockpiled for future use.
B. Preparation for Topsoil Placement:
1. Finish excavation and embankment work according to the specified grades and cross sections; grade and slope all surfaces to drain away from buildings and prevent ponding. Conform to the grading plan within ± 2 inches.
2. Loosen surface to a minimum depth of 4 inches to reduce compaction.
C. Topsoil Spreading and Finish Grading:
1. Place the topsoil after all grading and trenching activities in the area have been completed.
2. Place topsoil at least 8 inches deep; smooth and finish grade according to the contract documents. If topsoil is being amended with compost, thoroughly blend compost with on-site topsoil at the rate specified in 2010, 2.02, B.
3. After finish grading the topsoil, remove clods, lumps, roots, litter, other undesirable material, or stones larger than 1-inch (1/2-inch for turfgrass).
3.04 EXCAVATION
A. Notification: Notify Jurisdictional Engineer prior to start of excavation activities.
B. Removal and Stockpiling: Remove and stockpile top 8 inches of topsoil or as indicated in the contract documents for subsequent reuse.
C. Excavate: Excavate to the prescribed grade.
D. Rock Excavation: When excavation to the finish grade line results in a surface consisting of loose or solid rock, the Contractor shall:
1. Excavate one-foot below the finished subgrade.
2. No rock larger than 3 inches will be allowed within one-foot of the subgrade.
3. Subject to the approval of the Jurisdictional Engineer, the earth backfill may be obtained within the right-of-way where suitable material is available.
4. The Contractor shall conduct operations in such a way that the Jurisdictional Engineer is given the opportunity to cross-section before backfill.
E. Surface Removal:
1. Saw cut surface material to full depth as required and at designated removal lines.
2. Surface material broken or damaged by Contractor beyond designated removal lines shall be removed to new line designated by the Jurisdictional Engineer and replaced at the Contractor's expense.
3. Protect subgrade beneath existing surface removal areas.
4. Existing asphaltic concrete roadways.
a. Remove and stockpile all asphaltic materials.
b. If used for pavement subbase, material shall be processed by passing through a 1 1/2 inch flat sieve or 2 inch tilted vibrating screen.
c. Remainder of material shall be disposed of by:
1) Use as unsuitable soil in accordance with Section 2010, 3.06 E.
2) Remove excess to an approved landfill designated for this type of material or to a site designated by the Jurisdictional Engineer.F. Shaping of Borrows:
1. Borrow areas provided by the Contractor shall be regular in cross section to permit accurate measurement.
2. Care shall be taken to blend to natural land forms and avoid unnecessary damage to the land.
3. The Contractor shall not turn natural drainage of surface water on to adjoining owners and shall use strict diligence in draining the surface water in its natural course or channel.
4. Excavation shall be completed in a way as to be consistent with the existing natural drainage conditions.
G. Unsuitable or Unstable Materials:
1. Remove unsuitable or unstable materials to a depth specified by the contract documents, or as directed by the Jurisdictional Engineer.
2. Jurisdictional Engineer shall determine the need for and type of stabilization.
3. Remove all soft areas. Backfill with approved materials.
4. If stabilization materials are used, provide weight tickets at the time of delivery.
5. See Section 2010, 3.06 for disposal of unsuitable or unstable materials.
H. Drainage:
1. Provide temporary drainage facilities to prevent damage to public or private interests when necessary to interrupt natural drainage or flow of artificial drains.
2. Restore original drainage as soon as work permits.
3. The Contractor is responsible for damage resulting from their neglect to provide erosion control or artificial drainage.
I. Utility Poles: If impractical or scheduling does not permit the removal of utility poles before excavation, the Contractor shall be required to work around the poles.
J. Compaction: Unless otherwise specified by the contract documents, compaction of embankments 2 feet outside of the paved surface edge shall meet 95% of Maximum Standard Proctor Density and moisture range of optimum moisture to 4 percentage points above optimum moisture.
3.05 EMBANKMENT CONSTRUCTION
A. Notification: Notify Jurisdictional Engineer prior to start of embankment activities.
B. Construct to Prescribed Grade:
1. Horizontal layers not over 8 inches in loose thickness.
2. Each layer to be placed full width of embankment and smoothed to uniform depth by motor patrol, bulldozer, or other means acceptable to the Jurisdictional Engineer.
3. Soils containing roots, sod, or other vegetable matter upon approval of Jurisdictional Engineer may be deposited outside parking area or shoulder line and within 3 feet of the outer embankment limits.
4. Stone to be distributed throughout the embankment to avoid pockets. No stone larger than 3 inches within 1 foot of the subgrade.
5. No tree stumps or large woody objects in the embankment./p>
C. Step or Bench: Step or bench all existing slopes greater than 5 horizontal to 1 vertical to connect existing grade with new fill.
D. Runoff Control: Outer portion of embankment to be lower than center. If rain is likely to occur, smooth and compact to shed water.
E. Compaction with Moisture and Density Control: Unless otherwise specified in the contract documents, compaction with moisture and density control shall be required for construction of embankments.
Compaction of embankments shall meet 95% of Maximum Standard Proctor Density and moisture range of optimum moisture to 4 percentage points above optimum moisture. Testing requirement shall follow Section 2010, 3.10.
F. Type A Compaction: When Type A compaction is specified in the contract documents, the following shall apply:
1. Compact until full weight of sheepsfoot roller is supported entirely on its feet (walkout), but not less than one pass per inch of loose material.
2. Roller shall be considered supported when feet do not penetrate more than 3 inches into material being compacted.
3. Soil too wet to sufficiently compact.
a. Provide one discing per 2 inches of loose thickness.
b. Cut and stir full depth of layer.
c. Interval of not longer than 2 hours between successive discing.
d. Compact by specified rolling.
4. Soil too dry to sufficiently compact.
a. Moisten material.
b. Manipulate to secure uniform moisture.
c. Compact by specified rolling.
5. Compact adjacent to structure.
a. Place fill to same level as fill operation progresses.
b. Hand compact that which cannot be rolled by mechanical tamper.
6. The Contractor may substitute Compaction with Moisture and Density Control for Type A Compaction, providing all testing as required at no additional cost to the Jurisdiction.
3.06 UNSUITABLE SOILS
Unsuitable soils may be incorporated into the project only as specified by the Jurisdictional Engineer. See Figure 2010.1B. Place according to the following:
USE MATERIALS Slope Dressing only: 1. Peat of Muck.
2. Soils with a plasticity index of 35 or greater.
3. A-7-5 or A-5 (AASHTO) having a density less than 85 pcf (ASTM D 698 Standard Proctor Density).Type C Placement: Placed 3 ft. below subgrade in fills: (can be used 2 ft. outside curbline) 1. All soils other than A-7-5 or below subgrade A-5 having a density of 95 pcf or less (ASTM D 698 Standard Proctor Density).
2. All soils other than A-7-5 or A-5 containing 3.0% or more carbon.Type B Placement: Placed 5 ft. below subgrade and outside shoulders in fills: 1. A-7-6 (Plasticity index of 30 or greater)
2. Residual clays (overlying bedrock) regardless of classification.Type A Placement: Placed in layers (8" max. thicknes) 5 ft. below subgrade and 2 ft. outside curbline in fills: (Alternate layers shall be suitable soils or soils other than A-7-5 or A-5 containing 3.0% or more carbon.) 1. Shale
2. A-7-5 or A-5 soils having a density greater than 86 pcf but less than 95 pcf (ASTM D 698 Standard Proctor Density).E. Placed 4 ft. below subgrade in fills outside curbline: 1. Broken PCC in 6 inch sizes or smaller. (Pulverized ACC can be used as Subgrade replacement.) 3.07 SUBGRADE PREPARATION
A. Notification: Notify Jurisdictional Engineer prior to start of subgrade activities.
B. Shaping: Shape and consolidate subgrade in preparation for placement of pavement.
C. Uniform Compostion: Provide uniform composition of at least 12 inches below top of subgrade under new paving plus 2 feet on each side.
D. Subgrade Compaction in Fill Section: Subgrade compaction in fill sections shall meet 3.05 E.
E. Subgrade Compaction in Cut Sections:
1. Disk, scarify, mix and recompact the top 12 inches of subgrade with moisture and density control.
2. Disks (approximately 36 inches in diameter) and rollers (approximately 60" in diameter) to be adequately sized to insure moisture and density control at 12 inches.
3. If equipment is not sized to perform moisture and density requirements at minus 12 inches, then excavate top 6 inches of subgrade, scarify, mix, and recompact next 6 inches of subgrade with moisture and density control. Pulverize, mix, and replace top 6 inches of subgrade and compact.
4. Compact to not less than 95% Maximum Standard Proctor Density; moisture content not less than optimum or more than 4% above optimum moisture content.
F. Stones: Remove stones over 3 inches in size from subgrades.
G. Ruts: If ruts or other objectionable irregularities form in subgrade during construction, reshape and reroll subgrade before placing pavement; fill ruts or other depressions with material similar to other subgrade material and compact.
H. Future Trimming: Construct to elevation and cross section such that, after rolling, surface will be above required subgrade elevation.
I. Proof Roll: Proof rolling shall be performed with a truck loaded to the maximum single legal axle gross weight of 20,000 pounds or the maximum tandem axle gross weight of 34,000 pounds. Trucks shall be operated at less than 10 mph. One pass shall be made for every lane. The subgrade will be considered to be unstable if, under the operation of the loaded truck, the surface shows yielding (earth wave in front of the loaded tires) or rutting of more than 2.0 inches measured from the top to the bottom of the rut at the outside edges.
J. Unstable Material: If soft or yielding areas are located, remove unstable materials and replace with suitable materials and compact as specified.
K. Final Subgrade: Complete final subgrade by excavation to grade by use of steel-shod template supported on side forms or support rollers or by use of automatically controlled subgrade excavating machine.
L. Subgrade Check: Check subgrade elevation and grade by method approved by Jurisdictional Engineer prior to paving.
M. Subgrade Maintenance: Maintain subgrade prior to and during paving operations; repair any damaged or disturbed areas prior to paving.
3.08 SUBGRADE TREATMENT (Only if Required): When required, all the provisions and requirements of Section 2010, 3.07 (subgrade preparation) shall apply to subgrade treatment.
A. Lime or Fly Ash: Upon review of a Soil Engineer, lime or fly ash stabilization may be used as subgrade treatment.
1. Construct in 6 inch layers.
2. Scarify to the proper depth.
3. Incorporate the stabilizing material uniformly.
4. Test for support.
B. Polymer Grid: Upon review of the Jurisdictional Engineer, a polymer grid may be used to stabilize the subgrade or reinforce the pavement section.
1. A minimum of 6 inches of well graded granular backfill will be placed on the polymer grid.
2. Largest particle size of backfill will not exceed 1-1/2 inches with less than 10% passing the No. 200 sieve.
3. Installation shall adhere to the guidelines set forth by the polymer grid manufacturer.
3.09 GRANULAR SUBBASE (Class A, B, C, & D)
A. Subgrade: Subgrade to be compacted and shaped smooth before subbase material is placed.
B. Construction: Construct the specified type of granular subbase to the specified depth; extend to 2 feet outside the pavement area.
C. Moisture and Density: Special backfill and granular subbase shall be compacted to not less than 95 percent of maximum Standard Proctor Density or 70% Relative Density (ASTM D 4253 and D 4254). Moisture content not less than optimum or more than 4% above optimum.
D. Final Elevation:
1. Should the Contractor who constructed the subbase elect to overbuild the subbase, the Paving Contractor shall trim down to the design elevation and shape to the final template with an automatically controlled trimming machine. Excess material shall be salvaged and spread for use on any other approved project location or operation.
2. Conform to the design profile and cross section to the extent that no point is higher than the designed elevation and no point is lower than 0.05 foot below this elevation.
3. The top 1 inch of the subbase shall be uniformly moist prior to paving.
4. Hauling equipment and other traffic will not be allowed on completed Class B subbase (granular subbase).
3.10 FIELD QUALITY CONTROL
A. Compaction Testing: Provide compaction testing of embankment, using the services of an independent testing laboratory approved by the Jurisdictional Engineer, unless testing is provided by Jurisdictional Engineer.
B. Density: Obtain required compaction not less than 95% of maximum Standard Proctor Density.
C. Moisture Range: Obtain required compaction within a soil moisture range of optimum moisture to 4 percentage points above optimum moisture content.
D. Testing:
1. Lab Test: Determine laboratory density of material in accordance with ASTM D 698 (Standard Proctor Density) or ASTM D 4253 and D 4254 (Maximum and Minimum Index Density for Cohesionless Soils). Provide at least one analysis for each material type used as backfill unless provided by Jurisdictional Engineer.
2. Field Test: Perform in-place field density and moisture testing in accordance with ASTM D 2922 and D 3017 (nuclear) or ASTM D 1556 (sand cone) and D 2216 (moisture content).
3. Frequency:
a. Urban Section: Provide one test per lift per 150 feet. If section is less than 300 feet, a minimum of two tests per lift will be required.
b. Rural Section: Provide one test for each 500 cubic yards of material placed with a minimum of two tests per lift.
4. Show compliance with specifications.
5. Locations to be tested will be selected by Jurisdictional Engineer.
6. Additional testing may be required by Jurisdictional Engineer if noncompliance or change in conditions occur.
E. Test Failure: Rework, recompact, and retest as necessary until specific compaction is achieved in all areas of the embankment.
3.11 FIXTURE ADJUSTMENT
A. Manhole Adjustment: Refer to Section 6020 (1.08, 3.03) for manhole adjustment (minor and major).
B. Traffic Handhole:
1. Add adjustment rings as required, up to a total stack height of 16 inches to raise casting to finish elevation.
2. Remove one or more adjusting rings, as required, to lower casting to finish elevation.
C. Adjust Valve Box, Minor. Raise or lower existing adjustable valve box to finish grade.
D. Adjust Valve Box, Major. For existing boxes which do not have sufficient adjustment range to bring to finish grade, install new top sections or extensions as required.
E. Set existing hydrants at finished grade.
1. Add extension barrel sections and stems as necessary; paint exterior of new barrel section to match existing hydrant unless otherwise specified in the contract documents. See Section 5020 for color of hydrants.
2. Disinfect and test hydrant.
F. Fixture Adjustment in Pavement: Refer to Section 7010 and 7020 for additional requirements for adjustment of fixtures in pavement.
G. Set existing valve boxes, valve manholes, water service valves, etc., to finish grade of pavement, driveway, sidewalk, or topsoil; add extension sections as necessary.
3.12 TEMPORARY EROSION CONTROL DURING CONSTRUCTION
A. Topsoil Erosion: Insure that soil erosion is minimized and to prevent eroded soil from leaving the construction project onto adjacent property.
B. Comply with National Pollutant Discharge Elimination System (NPDES) Permit: If project disturbs more than 1 acre including off-site borrow and disposal areas, a "Notice of Intent" for NPDES coverage under General Permit No. 2 (Storm Water Discharge Associated with Industrial Activities for Construction Activities) shall be required. Unless specified otherwise, the Jurisdiction shall be responsible for filing the Notice of Intent.
C. Erosion Control Work Plan:
1. Submit for Jurisdictional Engineer approval.
2. Include:
a. Materials and equipment to be used.
b. Location and timing of silt fence and silt basins and other temporary erosion control measures.
c. Schedule for placement of stabilizing crop seeding.D. Controls:
1. Prior to site clearing and grading operations, install silt fence along the perimeter of the project on the downslope sides of the site and excavate the temporary siltation basins in the existing drainageway as shown on the plans.
2. Preserve existing vegetation in areas not needed for construction.
3. Provide temporary sediment basins at the rate of 3,600 cubic feet of storage per acre disturbed over 10 acres. If not attainable, a combination of silt fences, multiple sediment traps, or equivalent sediment controls are required for all side slopes and downslope boundaries of the disturbed area. For 10 or less acres disturbed, the same erosion controls are required except for sediment basin which is optional.
4. Provide additional siltation fence, temporary silt basins, diversion dikes, earth dikes, and/or straw bales around all storm sewer inlets and outlets.
5. Provide temporary and/or permanent seeding of areas upon completion of grading as soon as practical.
6. If construction activity is not planned to occur in a disturbed area for at least 21 days, the area shall be stabilized by temporary erosion controls within 14 days of ceasing construction activities.
7. Maintain all temporary and permanent erosion control measures in working order, including cleaning, repairing, replacement, and sediment removal throughout the permit period. Site must be inspected by a qualified person once every seven calendar days and within 24 hours after a rainfall of 0.5" or greater. Reports summarizing the inspections shall be made and retained as part of the storm water pollution prevention plan until project termination.
3.13 DUST CONTROL
A. Calcium Chloride: Tight blade road surface. Apply in solid or solution form at a rate which will deliver to the road surface one pound of calcium chloride per square yard when computed on an anhydrous basis (Iowa DOT 2314).
B. Lignosulfonate (Tree Sap): Tight blade road surface. Apply a minimum of one gallon of diluted solution per square yard.
3.14 PAVEMENT REPLACEMENT: See Division 7.
END OF SECTION