NV FLAP 400(1) Logandale Trails Pavements Report Signed 2024.pdf

LOGANDALE TRAILS ACCESS ROAD

CLARK COUNTY, NEVADA

NV FLAP 400(1)

PAVEMENT AND MATERIALS REPORT

JULY 2024

Report prepared by:

U.S. Department of Transportation Federal Highway Administration

Central Federal Lands Highway Division Lakewood, Colorado http://www.google.com/imgres?sa=X&biw=1280&bih=819&tbm=isch&tbnid=gtpyJEKxSQX6SM:&imgrefurl=http://portal.hud.gov/hudportal/HUD?src=/press/press_releases_media_advisories/2010/HUDNo.10-242&docid=0hzyuk4oobnONM&imgurl=http://portal.hud.gov/hudportal/images/hudimg?id=dot_logo_41193.jpg&w=520&h=528&ei=uGw7Uoy6Ksjk4AOC_IDQBw&zoom=1&iact=hc&vpx=567&vpy=131&dur=635&hovh=226&hovw=223&tx=151&ty=150&page=1&tbnh=154&tbnw=162&start=0&ndsp=30&ved=1t:429,r:26,s:0,i:171

NV FLAP 400(1) Logandale Trails Access Road ii

Written by: ________________________________________________________ Robert Norick, Staff Pavements & Materials Engineer

Reviewed by: ________________________________________________________ Mike Voth, Pavements & Materials Team Lead

Approved for distribution by:

Mike Voth, Pavements & Materials Team Lead

Electronic Distribution:

Construction Project Development Project Management Technical Services iii

TABLE OF CONTENTS

I. INTRODUCTION

II. CLIMATE

III. EXPLORATION

IV. SUBGRADE SOILS & GEOLOGY

V. PAVEMENT DESIGN INPUTS

VI. PAVEMENT RECOMMENDATIONS & DISCUSSION

VII. MATERIALS RECOMMENDATIONS

APPENDICES

A – Site and Boring Maps B – Boring Log and Lab Report C – Site Investigation Photos D – Pavement Design Calculations E – Asphalt Binder Selection & Climate Data F – Pipe Selection Criteria G – Project Specific SCRs

I. INTRODUCTION

This report is written to document the existing road conditions and to provide pavement recommendations for the planned NV FLAP 400(1) Logandale Trails Access Road in southern Nevada. The project proposes to pave the existing gravel access road from the west end of Liston Avenue within the Town of Logandale, west and uphill for approximately 3.25 miles to the Logandale Trails trailhead parking lot on the Bureau of Land Management property. Portions of the road are also located on Nevada State Park land and within Clark County right-of-way as shown on the Clark County GIS Site Map in Appendix A. The parking lot is located approximately 500 vertical feet above the Town of Logandale. Logandale is located 6 miles south of US Interstate 15 along State Highway 169; approximately 40 miles northeast of Las Vegas The road is currently gravel with an average width of 24 feet. The project proposes a 26 foot pavement width with 11 foot lanes and 2 foot shoulders in each direction.

II. CLIMATE

Climate data was obtained from the Western Regional Climate Center for the Logandale, Nevada weather station. This data is summarized in Table 1 below and provided in Appendix E. The project is within a desert area which has an average precipitation of approximately 5.14 inches/year. The project ranges in elevation from about 1,390 feet to 1,840 feet. The area receives moisture nearly entirely from rain. Often the rain comes in quick thunderstorms or monsoonal events that create flash flooding of dry ravines.

Table 1. Weather Data

Month Average

HIGH

Record

HIGH

Average

LOW

Record

LOW

Average

PRECIP.

January 58.9 77 31.2 12 0.65 February 65.5 92 36.0 18 0.59

March 70.7 92 40.5 25 0.74 April 79.1 101 45.6 30 0.15 May 89.2 109 54.7 37 0.27 June 100.2 116 62.1 40 0.06 July 105.1 119 68.8 48 0.51

August 102.2 116 68.0 49 0.58 September 95.7 110 60.4 37 0.40

October 83.9 103 48.9 22 0.36 November 69.0 92 38.6 21 0.43 December 59.9 76 30.7 7 0.40

Temperatures are in °F and precipitations are in inches.

III. EXPLORATION

On October 24, 2018, a pavement and subgrade investigation was conducted for the project consisting of six shallow hand augered borings (1 to 5 feet deep). The locations of the soil borings BH-1 through BH-5 are shown on the boring map in Appendix A. Boring BH-6 was located at the entrance to the trailhead parking lot near Milepost 3.1 as shown on the Clark County GIS Site Map in Appendix A. CFL personnel logged the findings including depth of boring and visual soil classification. During the site visit, five soil samples were collected. These samples were submitted to the CFLHD laboratory for soil classification and additional testing (R-Value, pH, resistivity, solubility, and salts). Silver State Analytical Labs of Las Vegas, Nevada performed the testing for solubility and salts (i.e. testing for expansive salt enriched soils). Geotechnical investigations in southern Nevada typically include this testing in an effort to identify the potential for damaging salt heave. The boring log and laboratory reports are provided in Appendix B.

IV. SUBGRADE SOILS & GEOLOGY

The current Logandale Trails Access Road is a gravel road constructed of the native soils.

This material requires frequent maintenance with bladed windrows along both edges of the road. The subgrade investigation found silty and clayey sands for the lower 1.3 miles (beginning at Milepost 0.0) and poorly graded sand with gravel for the upper 2 miles (a FP-14 subbase material). The site is located primarily within terrace deposits consisting of silt, sand, and gravel. Portions of the site may also lie within the Muddy Creek formation (siltstone and sandstone).

The Las Vegas Wash and the associated flood plains east of Las Vegas (southern Nevada) have areas with expansive salt enriched soils that behave like expansive clays and can damage lightweight structures (e.g. single family homes). The heave of these soils occur with the drop in temperature from day to night, absorbing water and swelling in the process, or as the result of poor drainage. Soils containing more than 0.2 percent of sodium sulfate may be subject to salt heave in varying degrees and for very localized areas. Research by Harold D. Blaser (Federal Housing Administration) and Oscar J.

Scherer (Nevada Testing Laboratory) indicates that the swelling beneath asphalt pavements can be eliminated with the placement of 12 inches or more of salt free granular material between the salt laden subgrade and the bottom of the pavement section; thereby buffering the subgrade soils from changing ambient temperatures and moistures. Alternatively, salt heave can be corrected by removing the affected subgrade soils (subexcavation). The Nevada DOT finds that it is not cost effective to mitigate the potential for salt heave for the entire length of a road. Rather, it is more cost effective to repair localized salt heave areas after the fact.

V. PAVEMENT DESIGN INPUTS

The pavement design for the Logandale Trails Access Road utilized design criteria established in the Federal Lands Highway Project Development Design Manual (PDDM) and the 1993 AASHTO Guide for Design of Pavement Structures (AGDPS). The criteria shown in Table 2 below were selected based on the project’s scope and traffic levels.

Table 2. Design Criteria Design Performance Period (3R) 20 years Initial Serviceability 4.2 Terminal Serviceability 2.0 Design Reliability Level 75% Overall Standard Deviation 0.49 Annual Traffic Volume Growth Rate 2.0% Directional Distribution (dead end road) 50%

Traffic

The road has two primary generators of traffic: 1) recreational traffic for the BLM trailhead and 2) local traffic for the residences along the first mile of the road. The BLM has a permanent traffic counter at the entrance to the trailhead parking lot (see Appendix D). The BLM traffic counter indicates a two-way average daily traffic (ADT) of 100 vehicles per day at the parking lot. Based upon the number of homes along the lower section of the road, the local traffic is conservatively estimated to be equal to the BLM trailhead traffic for a total two-way ADT of 200 vehicles per day. The vast majority of the vehicles that use this route are passenger vehicles, pickups, and SUVs; some pulling light travel trailers and off-road vehicles (FHWA Class 2-3 vehicles). Based upon site visit observations, truck traffic is estimated to be approximately 10% of the roads ADT; 9% Class 5 motor homes and 1% Class 6, three axle, garbage and septic trucks.

Accurate traffic load estimates expressed as 18-kip equivalent single axle loads (ESALs) are critical for the pavement design. Load estimates are based on vehicle counts and classifications with a 20-year, 2% growth factor of 24.3. Standard load equivalency truck factors are used to convert the various vehicle axle loads to 18-kip ESALs. The following truck factors were assumed for the aforementioned vehicle classifications in accordance with PDDM Exhibit 11.2-A: 0.001 for Class 2-3, 0.5 for Class 5, and 1.0 for Class 6.

Based upon the design criteria and assumptions shown above and the 1993 AASHTO pavement design procedure, the project’s 20-year-18-kip equivalent single axle loads (ESALs) are calculated to be 49,575 (see Appendix D). According to PDDM Section 11.2.1.2, a minimum of 50,000 ESALs shall be used for the design of paved roads.

Subgrade Soil Resilient Modulus

The project soils consist of silty and clayey sands and poorly graded sands with gravel.

For sands and gravels, the subgrade Resilient Modulus (MR) is calculated from the R-Value using the following correlation equation.

Resilient Modulus, MR (psi) = 10[ ( S

+ 18.72 ) / 6.24 ] where the S1 factor = [(R-Value – 5) / 11.29] + 3

Three subgrade soil samples were submitted to the CFLHD laboratory to determine their R-Values (resistance values on a scale of 0 to 100 per AASHTO T 190). The clayey sands of Borings BH-2 and BH-4 were found to have an R-Value of 20 and are representative of the subgrade soils along the lower 1.3 miles of the road. Based upon an R-Value of 20, the clayey sands between Mileposts 0 and 1.3 have a calculated design Resilient Modulus of 5,000 psi.

Between Mileposts 1.3 and 3.3 (Borings BH-5 and BH-6), the subgrade soils are FP-14 subbase material (based upon gradation, liquid limit, and plasticity index). FP-14 subbase materials typically have R-Values greater than 65 in accordance with PDDM Exhibit 11.2-C. An R-Value of 65 correlates to a Resilient Modulus of 21,500 psi.

Between Mileposts 1.3 and 3.3, the project’s pavement design utilizes a conservative Resilient Modulus value of 15,000 psi.

Structural Layer Coefficients

Standard CFLHD structural layer coefficients were selected for asphalt concrete pavement (0.40) and crushed aggregate base (0.14) in accordance with Exhibit 11.2-C of the PDDM. A drainage coefficient of 1.0 was utilized for all proposed layers.

Structural Number Calculations

The 1993 AASHTO pavement design procedure is used to determine the required pavement structural numbers (SN) for the project. Based upon the ESALs, the subgrade Resilient Modulus, and the aforementioned design criteria, the following required 20-year pavement design structural numbers are calculated for the project (See Appendix D).

Required SN between Mileposts 0 and 1.3 = 2.21 inches

Required SN between Mileposts 1.3 and 3.3 = 1.43 inches

VI. PAVEMENT RECOMMENDATIONS & DISCUSSION

Project Recommendations

After evaluating alternatives, the following pavement structural sections are recommended for the project:

Milepost 0.0 to 1.3

3 inches of Asphalt Concrete Pavement (SN = 3” x 0.40 = 1.20”) 8 inches of Crushed Aggregate Base (SN = 8” x 0.14 = 1.12”)

TOTAL SN = 2.32 inches

Milepost 1.3 to 3.3 3 inches of Asphalt Concrete Pavement (SN = 3” x 0.40 = 1.20”) 4 inches of Crushed Aggregate Base (SN = 4” x 0.14 = 0.56”)

TOTAL SN = 1.76 inches

VII. MATERIALS RECOMMENDATIONS, SCRs, AND

CONSTRUCTION CONSIDERATIONS

Selection of Asphalt Binder

The LTPPBind program and the PDDM standards were utilized for the selection of the asphalt binder for the project (See Appendix E). A PG 76-22NV binder is recommended for the project. The Nevada DOT uses this grade exclusively for southern Nevada.

Prime and Tack Coats, Fog Seal and Blotter

For this project, a Prime Coat and Blotter applied to the base prior to asphalt placement, a Tack Coat applied between asphalt lifts, and a Fog Seal applied to the final pavement surface are recommended.

Bid Items

The suggested FP-14 pay items for the proposed structural section are shown in Table 3.

Table 3: Recommended Pay Items Item Number Item Description Unit 30101-0000 Aggregate Base TON 40301-0100 Asphalt Concrete Pavement, Type 1 TON 40601-0000 Fog Seal TON 41102-1000 Prime Coat, Method 1 SQYD 41105-0000 Blotter TON 41201-0000 Tack Coat TON 50101-0800 Minor Concrete Pavement, Reinforced, 8-inch Depth SQYD

Materials for Culvert Pipe / Cement

The project’s sandy soils were found to be corrosive with resistivity as low as 245 ohm-cm. To address the corrosive soils, corrugated steel pipe with either 12 gage wall thickness or a polymer coating is recommended. Additionally, all Portland cement concrete to include cement with moderate sulfate resistance.

SCRs and Construction Concerns

CFLHD standard SCRs related to pavements and materials are expected to be used with the exception of the following FP-14 sections: Section 403 Asphalt Concrete; Section 602 Culverts and Drains; Section 701 Cement; and Section 702 Asphalt Material. For the 403 SCR, Subsection 403.01 to specify a PG 76-22NV asphalt binder. The 602 SCR to specify that pipe culverts to be constructed of corrugated steel pipe with either 12 gage wall thickness or a polymer coating. The 701 SCR to specify cement with moderate sulfate resistance. The 702 SCR to be tailored for the NDOT PG 76-22NV binder. These SCRs are provided in Appendix G. Any additional SCRs may be developed as needed.

APPENDICES

A – Site and Boring Maps

B – Boring Log and Lab Report

C – Site Investigation Photos

D – Pavement Design Calculations

E – Asphalt Binder Selection & Climate Data

F – Pipe Selection Criteria

G – Project Specific SCRs

APPENDIX A – Site and Boring Maps

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APPENDIX C – Site Investigation Photos

MP 0.0, BH-1, Looking Back, Red Silty Sand Subgrade

MP 0.3, BH-2, Looking Back, Reddish Tan Clayey Sand Subgrade

MP 0.7, BH-3, Looking Ahead, Reddish Tan Clayey Sand Subgrade

MP 1.1, BH-4, Looking Ahead & Uphill, Red Clayey Sand Subgrade

MP 1.4, BH-5, Looking Ahead & Uphill, Windrow of Red Sand with Grey Gravel

MP 1.8, Cut Slope of Red Sand with Grey Gravel

MP 1.8, Looking Ahead, Red Sand with Grey Gravel in Windrow & Cut Slope

MP 1.8, Looking Back & Downhill, Red Sand with Grey Gravel at Toe of Cut Slope

MP 2.1, Looking Back & Downhill, Windrows of Red Sand with Grey Gravel

MP 2.6, Looking Ahead, Windrow of Red Sand with Grey Gravel

MP 3.1, BH-6, Looking Ahead at Entrance to Parking Lot

MP 3.1, BH-6, Windrow of Red Sand with Grey Gravel

APPENDIX D – Pavement Calculations with Traffic Counts

BLM Traffic Counts for Vehicles Entering Parking Lot

APPENDIX E – Asphalt Binder and Climate Data

LTPPBind Data

APPENDIX F – Pipe Selection Criteria

Hydrology and Hydraulics December 2012

7-48 Roadway Hydraulics

7.3.5.5 Recommended Methods

Design and evaluate the performance of energy dissipators according to the methods presented in HEC 14. HEC 14 also contains procedures for estimating scour hole dimensions at pipe outlets.

7.3.5.6 Reporting

The design of outlet protection for culvert, ditch, or storm drain outlets should be supported by documentation containing, at a minimum, the following information:

● Project identification

● Location of proposed installation

● Hydraulic design calculations

7.3.5.7 Plans

For the location and design of riprap outlet protection, prepare plans showing all details necessary to construct the improvements according to the hydraulic design, including the following:

● Location

● Dimensions and extent of riprap

● Gradation

● Bedding and Filter Material or Geotextile

● Grading or slope details

7.3.6 ALTERNATIVE PIPE MATERIALS

It is Federal Lands Highway policy to specify alternative drainage pipe materials on all projects where feasible and to comply with the provisions of 23 CFR 635.411. All suitable pipe materials, including reinforced concrete, steel, aluminum, and plastic will be considered as alternatives for all new cross culverts and storm drain pipes on Federal Lands Highway projects.

Not all pipe materials are appropriate or applicable for all storm drain applications. The design of alternative drainage pipe materials should consider functionally equivalent performance in three areas: structural capacity, durability and service life, and hydraulic capacity. The service life and hydraulic capacity issues are addressed in this section.

7.3.6.1 References

The following references provide source information for the development of the standards, criteria, and guidance of this subsection (most recent editions apply):

1. 23 CFR 635.411 Title 23 CFR 635.411 in 23 CFR 635D, General Material Requirements

Roadway Hydraulics 7-49

2. FHWA-FLP-91-006 FHWA, Durability of Special Coatings for Corrugated Steel Pipe, FHWA FLP-91-006

3. FHWA-RD-97-140 FHWA, Durability Analysis of Aluminized Type 2 Corrugated Metal Pipe, FHWA RD-97-140, 2000.

4. AASHTO HDG

Vol. IV

AASHTO Highway Drainage Guidelines, Volume IV – Hydraulic Design of Culverts

5. AASHTO HDG

Vol. XIV

AASHTO Highway Drainage Guidelines, Volume XIV – Culvert Inspection and Rehabilitation

6. Caltrans Chapter

California Department of Transportation Highway Design Manual, Chapter 850 – Physical Standards

7.3.6.2 Design Standards

7.3.6.2.1 Service Life

Design cross culvert and storm drain pipes with a minimum maintenance-free service life of 50-years, regardless of pipe material selection. A shorter service life may be used for temporary installations, and a longer service life may be considered in unusual situations.

7.3.6.2.2 Minimum Pipe Classification

Use Class II as the minimum for all reinforced concrete pipes. Determine appropriate pipe class from FLH fill height FLH Standard Drawings.

Use a minimum wall thickness of 0.0625” [1.63 mm] for all steel and aluminum pipes. The appropriate minimum structural metal thickness will be determined from approved FLH fill height tables.

7.3.6.3 Design Guidance

7.3.6.3.1 Service Life

The durability and service life of a storm drain pipe is directly related to the environmental conditions encountered at the site and the type of materials and coatings from which the pipe was fabricated. The two primary causes of early failure in drainage pipe materials are corrosion and abrasion.

Corrosion gradually wears away at the pipe walls by chemical action, and can occur from both the soil and water sides of the pipe. Abrasion wears away at the interior pipe wall by friction from suspended or bed-load sediment.

http://www.fhwa.dot.gov/publications/research/infrastructure/hydraulics/97140/97140.pdf http://www.fhwa.dot.gov/publications/research/infrastructure/hydraulics/97140/97140.pdf http://www.dot.ca.gov/hq/oppd/hdm/pdf/chp0850.pdf

7-50 Roadway Hydraulics

7.3.6.3.2 Data Collection

Corrosion

Representative pH and resistivity determinations are required in order to specify pipe materials capable of providing a maintenance-free service life. Samples are taken in accordance with the procedures described in AASHTO T 288 and T 289. Samples should be taken from both the soil and water side environments to ensure that the most severe environmental conditions are selected for determining the service life of the drainage pipe. Soil samples should be representative of backfill material anticipated at the drainage site. Avoid taking water samples during flood flows or for two days following flood flows to ensure more typical readings. In locations where streams are dry much of the year, water samples may not be possible or necessary. In areas of known uniform pH and resistivity readings, a random sampling plan may be developed to obtain the needed information.

In corrosive soil conditions where water side corrosion is not a factor, consider specifying less corrosive backfill material to modify the soil side environment. The mitigating effect of the specified backfill should be taken into account in making alternative pipe materials selections in situations where the soil side conditions control the design.

Abrasion

An estimate of the potential for abrasion is required in order to determine the need for invert protection. Four levels of abrasion are referred to in this guidance and the following guidelines are established for each level:

● Level 1. Nonabrasive conditions exist in areas of no bed load and very low velocities.

This is the condition assumed for the soil side of drainage pipes.

● Level 2. Low abrasive conditions exist in areas of minor bed loads of sand and velocities of 5 ft/s [1.5 m/s] or less.

● Level 3. Moderate abrasive conditions exist in areas of moderate bed loads of sand and gravel and velocities between 5 ft/s and 15 ft/s [1.5 m/s and 4.5 m/s].

● Level 4. Severe abrasive conditions exist in areas of heavy bed loads of sand, gravel, and rock and velocities exceeding 15 ft/s [4.5 m/s].

Abrasion levels are intended as guidance to help the engineer consider the impacts of bed-load wear on the invert of pipe materials. Sampling of the streambed materials is not required, but visual examination and documentation of the size of the materials in the stream bed and the average slope of the channel will give the designer guidance on the expected level of abrasion.

Where existing culverts are in place in the same drainage, the conditions of inverts should also be used as guidance. The expected stream velocity should be based upon a typical flow (i.e., 2-year flow and less) and not a 10-or 50-year design flood.

Roadway Hydraulics 7-51

7.3.6.3.3 Reinforced Concrete Pipe

Reinforced concrete pipe (AASHTO M 170M) is typically specified as an alternative whenever environmental conditions permit. The appropriate pipe class is determined from approved FLH fill height FLH Standard Drawings. If the following guidance on corrosion and abrasion limitations is used, reinforced concrete pipe can be assumed to have a minimum service life of

50 years.

Corrosion

Reinforced concrete pipe should not be specified for extremely corrosive conditions where the pH is less than 3.0 and the resistivity is less than 300 Ω-cm. Where the pH is less than 4.0, or the pipe is exposed to wetting and drying in a salt or brackish water environment, protective coatings (e.g., epoxy resin mortars, poly vinyl chloride sheets) should be used. When the sulfate concentration is greater than 0.2% in the soil or 2,000 parts per million in the water, Type

V cement should be specified. When the sulfate concentration is greater than 1.5% in the soil or 15,000 parts per million in the water, Type V cement should be used with a sulfate resistant pozzolan. A higher cement ratio may also be used (e.g., AASHTO Class V pipe design).

Abrasion

On installations in severe abrasive environments, consider using seven or eight sack concrete or increasing the cover over the reinforcing steel.

7.3.6.3.4 Steel Pipe with Metallic Coatings

Steel pipe will typically be specified as an alternative when the environmental conditions permit.

The appropriate minimum structural metal thickness is determined from approved FLH fill height tables. Federal Lands Highway design policy assumes that steel pipe will provide a useful, maintenance-free service life for a period of time beyond the point of first perforation. This assumes an acceptable risk for most Federal Lands Highway projects, but at locations with erodible soils, large traffic volumes, or high fills where replacement or repair would be unusually difficult or expensive, consider increasing the steel plate by one standard thickness. In unusual situations where very high fills and severe abrasion are combined, or where other environmental concerns would make replacement of a pipe culvert very costly or impractical, consider using a pipe one size larger in diameter to permit re-lining in the future by insertion of another pipe.

The following types of steel pipe with metallic coatings are considered as alternatives on

Federal Lands Highway projects:

● Galvanized steel (AASHTO M 218)

● Aluminum coated steel (Type 2) (AASHTO M 274)

Corrosion

Under non-abrasive and low-abrasive conditions, the service life of steel pipe with metallic coatings may be determined based upon corrosion (i.e., pH and resistivity) factors determined from Exhibit 7.3-B, which shows the relationship between service life and corrosion for plain

7-52 Roadway Hydraulics galvanized steel pipe. It has been adapted from the California Department of Transportation

“Method for Estimating the Service Life of Steel Culverts,” California Test 643. The curves have been modified to show the expected average service life of pipe with a steel thickness of

0.0625” [1.63 mm] assuming a useful, maintenance-free service life 25 percent longer than the number of years to first perforation. Under moderate and severe abrasive conditions, abrasion protection must also be considered.

Under nonabrasive and low abrasive conditions, the metal thickness of galvanized and aluminum coated steel (Type 2) alternatives should be determined from Exhibit 7.3-B based on the resistivity and pH of the site. The minimum metal thickness of steel pipe, as determined from FLH standard fill height tables, may have to be increased, or the additional life of a protective coating may have to be added, in order to provide a 50-year service life. The results included in FHWA-FLP-91-006 indicate that within the environmental range of 5.0 through

9.0 pH and resistivity equal to or greater than 1500 Ω-cm, aluminum coated steel (Type 2) can be expected to give a service life of twice that of plain galvanized pipe.

Exhibit 7.3-B can be used to determine various combinations of increased thicknesses, aluminum coated steel (Type 2), and protective coatings to achieve a 50-year service life, but in no case may the metal thickness specified by the structural requirements be reduced.

Abrasion

Under nonabrasive and low abrasive conditions, the metal thickness of the galvanized, galvalume, and aluminum coated steel alternatives, as determined from Exhibit 7.3-B, should be used.

On installations in moderate abrasive environments where protective coatings are not required for corrosion protection, the thickness of the metal should be increased by one standard metal pipe thickness determined from the diagram for average service life of plain galvanized culverts

(see Exhibit 7.3-B) or invert protection should be provided. Invert protection may consist of bituminous coating with invert paving with bituminous concrete, Portland cement concrete lining, installation of metal plates or rails, or velocity reduction structures.

On installations in severe abrasive environments where protective coatings are not required for corrosion protection, the thickness of the metal should be increased by one standard metal pipe thickness determined from the diagram for average service life of plain galvanized culverts (see

Exhibit 7.3-B) and invert protection should be provided. Invert protection may consist of installation of metal plates or rails, or velocity reduction structures.

Protective coatings are not suitable for corrosion protection in moderate-abrasive and severe abrasive locations. Metal pipes should not be specified in moderate and severe abrasive environments where coatings are required to protect against water-side corrosion.

Roadway Hydraulics 7-53

Exhibit 7.3-B ESTIMATING STEEL PIPE SERVICES LIFE

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7-54 Roadway Hydraulics

7.3.6.3.5 Non-Metallic Protective Coatings for Steel Pipe

Protective coatings may be used to provide additional protection from corrosion or abrasion resulting in an extended service life. Coatings to protect against corrosion may only be used in non-abrasive and low abrasive environments.

The additional service life noted below in bold for each type of protective coating, for corrosion protection, are from Part V of FHWA-FLP-91-006. The added service is applicable only to non-abrasive and moderate abrasive conditions. All of the following types of steel pipe with non-metallic coatings are considered as alternatives on Federal Lands Highway projects:

Bituminous coating

Bituminous coatings (AASHTO M 190) can be expected to add 10 years of service to the water side and 25 years life to the soil side service life of pipe as determined from Exhibit 7.3-B.

Bituminous-coated pipe should not be used in low abrasive environments.

Bituminous paving and coating

Bituminous paved invert with bituminous coatings (AASHTO M 190) can be expected to add

25 years life to water side locations. Under moderate abrasive conditions, bituminous paved pipe may be used for invert protection where corrosion protection is not required.

Concrete lining

Concrete lining (ASTM A 849) can be expected to add 25 years of service life. Due to the natural cracking of concrete, the concrete lining should be applied over an asphalt coating if corrosion protection is needed. Under moderate abrasive conditions, concrete lined pipe may be used for invert protection where corrosion protection is not required.

Polymer coating

Ethylene Acrylic Acid Film coatings (AASHTO M245 and M246) should provide an additional

30 years service life with a 0.009” [0.25 mm] thickness.

Aramid fiber bonded coating

Only limited data is available for the service life of aramid fiber bonded coated (ASTM A 885) and epoxy coated pipes. No additional service life is currently credited with this policy.

7.3.6.3.6 Aluminum Alloy Pipe

Aluminum alloy pipe (AASHTO M 196M) will typically be specified as an alternative when environmental conditions permit. The appropriate minimum structural metal thickness is determined from approved FLH fill height tables. Within the following limits of corrosion and abrasion, aluminum alloy pipe can be assumed to have a service life of 50 years. Additional service life may be achieved where required by abrasion with the addition of protective coatings or additional metal thickness as discussed below:

Roadway Hydraulics 7-55

Corrosion

An aluminum alloy should be allowed if the pH is between four and nine and the resistivity is greater than 500 Ω-cm. An aluminum alloy alternative can also be considered for use in salt and brackish environments when embedded in granular, free draining material.

Abrasion

On installations in non-abrasive and low-abrasive environments, abrasion protection is not required.

On installations in moderately abrasive environments, the thickness should be increased by one standard metal thickness or invert protection should be used. Invert protection may consist of bituminous coating and invert paving with bituminous concrete or Portland cement concrete, installation of metal plates or rails, or velocity reduction structures.

On installations in severe abrasive environments, the thickness of the metal should be increased by one standard metal pipe thickness from that determined for low-abrasive conditions and invert protection should be provided. Invert protection may consist of installation of metal plates or rails or velocity reduction structures.

7.3.6.3.7 Plastic Pipe

Polyethylene and polyvinyl chloride plastic pipe may be specified as alternatives for pipe diameters and minimum resin cell classifications shown in the AASHTO’s Standard Specifications for Highway Bridges, Division I Design, Section 18, Soil Thermoplastic Pipe

Interaction Systems. The thickness of the plastic alternatives must meet the structural requirements of AASHTO’s Standard Specifications. The assumed service life of plastic pipe designed in accordance with AASHTO Section 18 is 50 years. The maximum allowable fill heights for pipe materials listed below is determined from approved FLH standard fill-height tables which include the following plastic pipe materials:

● Smooth wall polyethylene (ASTM F 714)

● Corrugated polyethylene (AASHTO M 294)

● Ribbed polyethylene (ASTM F 894)

● Smooth wall polyvinyl chloride (AASHTO M 278 and ASTM F 679)

● Ribbed polyvinyl chloride (AASHTO M304 and ASTM F 794)

Corrosion

Plastic alternatives may be specified without regard to the resistivity and pH of the site.

Abrasion

Under nonabrasive and low-abrasive conditions, polyethylene and polyvinyl chloride alternatives should be allowed. Plastic alternatives should not be used under moderate and severe abrasive conditions without invert protection.

7-56 Roadway Hydraulics

Maximum Size

Limit the size of plastic pipe to 48” [1200 mm] under mainline roads.

The locations selected for use of plastic pipes should address partner agency concerns of possible damage due to fire, ultraviolet sunlight, and rodents.

7.3.6.4 Recommended Methods

Design and evaluate the design service life for galvanized steel culvert and storm drain pipes by the Modified California method presented in Exhibit 7.3B. Refer to FHWA-RD-97-140, Durability Analysis of Aluminized Type 2 Corrugated Metal Pipe, for design guidance on aluminized material.

7.3.6.5 Reporting

Documentation of the design service life of culvert and storm drain pipes should be included in the design reporting.

7.3.6.6 Plans

For culvert and storm drain pipes, include information on pipe material, size, class, gauge, and any special coatings in the Plan Drainage Summary.

APPENDIX G – Project Specific SCRs

Section 403. — ASPHALT CONCRETE

Description

403.01 Add the following:

A PG 76-22NV asphalt binder in accordance with Subsection 702.01 is required..

Construction Requirements

403.02 Composition of Mix (Job-Mix Formula). Add the following:

The CO may perform mix design-verification testing to confirm the mix meets the contract requirements. If verification testing is required, submit a loose mix sample to the CO 14 days prior to placement.

403.08 Placing and Finishing.

(a) Add the following:

Use a material transfer vehicle (MTV) with storage and remixing capabilities on all mainline construction for placing asphalt concrete mixtures. The MTV will independently remix and deliver mixture from the hauling equipment to the paving equipment.

Furnish an MTV with the following:

(1) Independently operated with its own driver/operator;

(2) Independent from the paver;

(3) A loading system with the ability to receive mixtures from hauling equipment;

(4) A minimum storage capacity of 15 tons (13.6 metric tons) with a remixing system in the material storage bin;

(5) Remixing capability within the storage bin;

(6) A discharge conveyor to deliver the mixture to the paver hopper; and

(7) A mass not exceeding the maximum legal loadings on structures.

Pick-up machines, hopper inserts, and material transfer devices are not considered MTVs.

In the event the MTV malfunctions during paving operations, the Contractor must suspend paving, however mix in transit and stored in the silo at the time of breakdown may be placed without the use of an MTV. Do not resume mix placement until the MTV is operational.

403.09 Compacting. Add the following:

For HMA, do not roll the mix after the surface cools below 175 ºF (80°C).

Along forms, curbs, headers, walls, and other places not accessible to the rollers, compact the mix with alternate equipment to obtain the required compaction.

403.12 Acceptance. Add the following:

During production placement of the mix, sample loose mix and compacted cores according to Table 403-2 and submit to the CO for acceptance. Materials that do not meet the approved job-mix formula are considered unacceptable.

Delete Table 403-2 and substitute the following:

Table 403-2 Sampling, Testing, and Acceptance Requirements

Material or

Product (Subsection)

Type of Acceptance (Subsection)

C ha ra ct er is tic es t M et ho ds

Sp ec ifi ca tio ns

Sampling Frequency

Point of Sampling Sp lit pl e

Reporting Time

R em ar ks

Mix Design Asphalt concrete mixture Type I

(403.02(a))

Measured and tested for conformance

(106.04)

Job-mix formula

Subsection 403.02(a)

When requested by the CO.

Flowing mix stream (bin or belt discharge) or behind the paver before compaction.

Yes Before approval of job-mix formula

Tested by the

CO

Production Asphalt concrete, Type I

(403.02(a))

Measured and tested for conformance

(106.04)

Job-mix formula

Density (1)

Maximum specific gravity

Subsection 403.02

AASHTO

T 166

T 209 (2)

1 per 700 tons (650 metric tons)

Behind the paver before compaction.

In-place after Compacting

Behind the paver before compaction

Yes hours

Deliver cores to

CO

for testing

Surface Tolerance

Straightedge measurement, Subsection 403.11

Continuously, after compaction

Finished pavement surface

No “

Placement temperature

− First load and as determined by CO thereafter

Hauling vehicle before dumping, or windrow before pickup

" Upon completion of measurement

Table 403-2 (continued)

Sampling, Testing, and Acceptance Requirements

Material or Product

(Subsection)

Type of Acceptance (Subsection)

C ha ra ct er is tic es t M et ho ds

Sp ec ifi ca tio ns

Sampling Frequency

Point of Sampling Sp lit pl e

Reporting Time

R em ar ks

Production Process control (153.03)

Gradation at the plant

T 27 & T 11

Contractor determined

Cold feed or hot bins as applicable

" 24 hours

Moisture content of aggregates

T 255

" Stockpile " " −

Density ASTM D2950

1 per 500 feet

(150 meters)

In-place after compacting

Asphalt concrete, Type II

(403.02(b))

Measured and tested for conformance

(106.04)

" " 3 per 700 tons

(650 metric tons)

In-place after compacting

(1) Dry cores to constant mass at 125±5°F (52±3 °C) or vacuum dry, ASTM D7227 before testing. For asphalt concrete Type I, cut two 6-inch (150-millimeter) diameter side by side cores. Remove them with a core retriever and fill and compact the core holes with asphalt concrete mixture. Label the cores and protect them from damage due to handling and temperature. Submit one core for verification testing. Dry the other core to constant mass at 125±5 °F (52±3 °C) or vacuum dry it according to ASTM D7227 before performing the core density and measuring the thickness. Use

62.245 pounds per cubic foot (997.1 kilograms per cubic meter) to convert specific gravity to density. Use AASHTO T 166 regardless of the volume of water absorbed. Use the average maximum specific gravity value (AASHTO T 209) of the first three samples to determine the percent compaction of each Lot.

(2) Do not use the dry back method (Section 11 of AASHTO T 209).

Section 602. — CULVERTS AND DRAINS

602.01 Description. Add the following:

Pipe culverts to be constructed with corrugated steel pipe with either 12 gage wall thickness or a polymer coating.

Section 701. — CEMENT

701.01 Hydraulic Cement. Delete the subsection and substitute the following:

701.01 Hydraulic Cement. Do not mix cement brands and types.

(a) Portland cement. Type II conforming to AASHTO M 85.

(b) Blended hydraulic cement. Conform to AASHTO M 240 and be designated with the suffix “(MS)” for moderate sulfate resistance.

Section 702. — ASPHALT MATERIAL

702.01 Asphalt Binder. Delete the Subsection and add the following:

702.01 Asphalt Binder. Conform to M 320, Table 1.

In AASHTO M 320, Table 1 replace footnote g with the following:

g If the creep stiffness is below 300 MPa, the direct tension test is not required. If the creep stiffness is between 301 and 600 MPa, the creep stiffness value shall be used. The m-value requirement must be satisfied in both cases.

702.01 Asphalt Binder. Add the following:

Asphalt binder for the asphalt concrete pavement will be Grade PG 76-22NV conforming to

Table 702-2. Blend the PG 76-22NV at the source of supply and deliver as a completed mixture to the job site. Do not transport PG 76-22NV by railroad car.

Table 702-2

Asphalt Binder Grade PG 76-22NV

Test Test Method Requirement

Tests on Original Binder:

Viscosity @ 135°C, Pas AASHTO T 316 3.00 Max.

Dynamic Shear, G*/sin , Test Temp 76°C @

10 rad/s, kPa AASHTO T 315 1.30 Min.

Ductility @ 4°C, 5 cm/min, cm AASHTO T 51 20 Min.

Polymer Content, % by mass (1) 3.0 Min.

Tests on Residue from R.T.F.O., AASHTO T 240:

Mass Loss, % AASHTO T 240 0.50 Max.

Dynamic Shear, G*/sin , Test Temp 76°C @

10 rad/s, kPa AASHTO T 315 2.20 Min.

Multiple Stress Creep Recovery, Test Temp 76°C

@ 3200 Pa, % AASHTO TP 70 25 Min.

Ductility @ 4°C, 5 cm/min, cm AASHTO T 51 10 Min.

Tests on Residue from Pressure Aging Vessel, AASHTO R28 @ 110°C:

Dynamic Shear, G*sin , Test Temp 31°C @

10 rad/s, kPa AASHTO T 315 5000 Max.

Creep Stiffness, S, Test Temp 12°C @

60 sec, MPa AASHTO T 313 (2) 300 Max.

Creep Stiffness, m-value, Test Temp 12°C @

60 sec AASHTO T 313 (2) 0.300 Min.

Direct Tension, Failure Strain, Test Temp 12°C

@ 1.0 mm/min, % AASHTO T 314 (2) 1.00 Min.

(1) Certificates of compliance provided for the material shall certify that the minimum polymer content is present.

(2) If the creep stiffness is below 300 MPa, the direct tension test is not required. If the creep stiffness is between 300 and 600 MPa, the direct tension failure strain can be used in lieu of the creep stiffness requirement. The m-value requirement must be satisfied in both cases.