TX FTNP BIBE 14(2)13(5)11(3) Pavement Report Signed.pdf

BIG BEND NATIONAL PARK

CHISOS BASIN AND WEST & NORTH ENTRANCE ROADS

BREWSTER COUNTY, TEXAS

TX FTNP BIBE 14(2), 13(5), 11(3)

PAVEMENT AND MATERIALS REPORT

FEBRUARY 2019

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

TX FTNP BIBE 14(2), 13(5), 11(3) Chisos Basin and West & North Entrance Roads iii

TABLE OF CONTENTS

I. INTRODUCTION

II. PAVEMENT EXPLORATION

III. EXISTING PAVEMENT & SOILS

IV. CONSIDERATIONS FOR EXPANSIVE & CORROSIVE SOILS

V. CLIMATE

VI. PAVEMENT DESIGN INPUTS

VII. PAVEMENT RECOMMENDATIONS & DISCUSSION

VIII. MATERIALS RECOMMENDATIONS

APPENDICES

A – Vicinity Map & Traffic Data B – Boring Log and Lab Report C – Site Investigation Photos D – Pavement Design Calculations E – Asphalt Binder Selection & Climate Data

I. INTRODUCTION

This report is written to document the existing pavement conditions and provide recommendations for the planned TX FTNP BIBE 14(2), 13(5), 11(3) project for the rehabilitation/repair of the following five road sections within Big Bend National Park (NP) in Brewster County, Texas. The locations of the road sections are shown on the Vicinity Map in Appendix A.

1. North Entrance Road (Route 11) repair at Milepost 24.8

2. Chisos Basin Road (Route 14) between Mileposts 0 and 6.25.

3. Ross Maxwell Road (Route 15) repairs at Mileposts 14.25 and 16.5.

4. West Entrance Road (Route 13) repair at Milepost 14.5.

5. West Entrance Road (Route 13) between Mileposts 22.65 and 21.75.

II. PAVEMENT EXPLORATION

On May 9-10, 2018, a pavement and subgrade investigation was conducted for the project consisting of twenty-seven shallow borings (5’ to 10’ depth) and one deep boring (20’ depth). CFL personnel logged the findings including depth of boring, visual soil classification, pavement and aggregate base thicknesses, and areas of distress. During the site visit, sixteen soil samples were collected. These samples were submitted to the CFLHD laboratory for soil classification and R-Value testing. The samples were not tested for corrosivity (pH, resistivity, sulfates, and chlorides) since previous pavement reports for the park have established the highly corrosive nature of the park’s soils. The boring log and laboratory report are provided in Appendix B. The boring log references the milepost locations of each boring along the various routes.

III. EXISTING PAVEMENT & SOILS

The existing pavement was found to be asphalt concrete pavement in fair to poor condition. The pavement and subgrade conditions at the aforementioned five road sections are summarized below.

1. North Entrance Road (Route 11) at Milepost 24.8 (elevation 2,680 feet above sea level). Milepost 0 is at the south end of the road at the intersection with Route 13 at Panther Junction. The North Entrance Gate (Persimmon Gap) is located at approximately Milepost 26.7. The existing pavement section generally consists of 3 inches of asphalt over a minimum of 5 inches of road base material. Beneath the road base are varying depths of gravel borrow material (0 to 7 feet deep) underlain by an expansive sandy lean clay. The asphalt is in poor condition with bumps, rutting, and block cracking from the underlying clay soils.

2. Chisos Basin Road (Route 14) between Mileposts 0 and 6.25. Milepost 0 is at the north end of the road at the intersection with Route 13. Elevations along the road range between 4,000 feet and 5,760 feet. Milepost 6.25 is located on the south end of the road at the entrance to the Chisos Mountain Lodge parking lot. The existing pavement section generally consists of 4 to 5 inches of asphalt over 4 inches of road base material. For the southern two miles of the roadway, the subgrade soils beneath the road base are clayey sands and gravel and the asphalt is in poor condition with transverse, longitudinal, and block cracking, in addition to, a continuous utility trench patch. For the northern four miles, the subgrade soils beneath the road base are generally poorly graded gravels with clay and sands. In this area, the asphalt pavement is in fair condition with fewer distresses.

3. Ross Maxwell Road (Route 15) repairs at Milepost 14.25 (elevation 2,920 feet) and Milepost 16.5 (elevation 2,650). Milepost 0 is located at the north end of the road at the intersection with Route 13. The Castolon Visitor Center is located on the south end of the road near Milepost 23 at elevation 2,170 feet. The existing pavement section consists of 4 to 5 inches of asphalt over 1 to 2 feet of a gravel borrow material. The underlying subgrade soils are expansive fat clays. The asphalt is in fair condition with bumps from the underlying clays soils.

4. West Entrance Road (Route 13) at Milepost 14.5 (elevation 3,275 feet). The west park boundary is located near Milepost 22.65. The existing pavement section consists of 3.5 inches of asphalt over nearly 3 feet of a gravel borrow material.

The underlying subgrade soils are expansive fat clays. The asphalt is in fair condition with a bump and cracking from the underlying clays soils. This section of the road was repaired within the past decade in an attempt to address the swelling soils, but with little success.

5. West Entrance Road (Route 13) between west park boundary at Milepost 22.65 (elevation 2,545 feet) and the West Entrance Gate (Maverick Junction) near Milepost 21.75 (elevation 2,735 feet). The existing pavement section consists of 3 to 4 inches of asphalt over 1 to 2 feet of a gravel borrow material. The underlying subgrade soils are expansive fat and lean clays. The asphalt is in fair condition with bumps and longitudinal cracking from the underlying clay soils, in addition to, transverse and block cracking.

IV. CONSIDERATIONS FOR EXPANSIVE & CORROSIVE SOILS

Previous projects at Big Bend National Park have documented both expansive and corrosive soils within the park. The following reports were reviewed as part of the pavement investigation.

1. 1985 Pavement Report for the Big Bend NP West Entrance Project: Report documented highly corrosive soils in area and recommended non-corrosive backfill for proposed culverts.

2. 1986 & 1987 Pavement Reports for the Big Bend NP West Entrance Project:

Reports documented highly corrosive soils in area and recommended Type V cement for concrete pipe or that culverts be backfilled with non-corrosive soils.

3. 1989 Pavement Report for Big Bend NP Chisos Basin, Route 14: Report documented highly corrosive soils in area and recommended that culverts be either plastic pipe or concrete pipe with Type V cement or be backfilled with non-corrosive soils.

4. 1989 & 1991 Pavement Reports for Big Bend NP Ross Maxwell Road, Route 15:

Reports documented highly corrosive soils in area and recommended that culverts be either plastic pipe or concrete pipe with Type V cement or be backfilled with non-corrosive soils or lean concrete backfill with Type V cement.

The 1989 report also documented expansive clay soils along the route and recommended an impermeable fabric over the roadway and ditches to prevent water from entering the clay soils.

5. 1993 Pavement Report for Big Bend NP Roads: This report documented the road distresses caused by the swelling of underlying expansive clays within the park. In 1980, a section of the North Entrance Road was raised 3 to 5 feet in an attempt to mitigate for the expansive soils, only to have cracks appear within one year. Bumps from swelling soils were also documented for Chisos Basin Road, Ross Maxwell Road, and the West Entrance Road. Swell tests of the clays showed very high swell pressures. It would take considerable loading to prevent upward movement; up to an 80 foot depth of embankment surcharge. The report proposed lime treatment of the top 8 inches of the clay subgrade for bumps at both Ross Maxwell and Chisos Basin. The report also proposed test sections along the North Entrance Road for the use of geogrids and support fabrics.

6. West Entrance Road (Route 13) at Milepost 14.5: Within the past decade, a bump in the area was repaired by placing three feet of borrow material above the expansive clay subgrade. The bump from the swelling clay soils has returned.

Previous projects within the park have seen minimal success in preventing pavement damage from expansive soils. Previous efforts have included the placement of 3 to 5 feet of borrow material above the expansive soils, lime treatment of the top 8 inches of the clay subgrade, and the use of geogrids. For a long-term solution, expansive soils should be removed for a minimum depth of 10 feet below the pavement section and replaced with non-expansive borrow material. For the current project, this is an impractical and uneconomical solution. The project was discussed with TXDOT’s Area Engineer, Chris Weber (Alpine, Texas). Chris Weber indicated that TXDOT has not identified a feasible, economical solution for the area’s expansive clay soils. TXDOT’s practice is to mill and overlay heave areas every three to four years.

V. CLIMATE

Climate data was obtained from the Western Regional Climate Center for the park’s Castolon Visitor Center and Chisos Basin. The park’s climate data is summarized in Table 1 below and provided in Appendix E. The high temperatures in the park occur at lower elevations such as the Castolon Visitor Center (elevation 2,170). The low temperatures in the park occur at the higher elevations of Chisos Basin (elevations above 4,000 feet). Table 1’s high and low temperatures are from the Castolon and Chisos Basin climate data, respectively. The average annual precipitation for Castolon and Chisos Basin is approximately 10.2 inches and 17.7 inches, respectively. Chisos Basin Road receives both snow and rain depending upon the time of year; approximately 2 inches of snow annually. The other four road sections receive only rain.

Table 1. Climate Data

Month Castolon Mean High

Castolon Record High

Chisos Basin Mean Low

Chisos Basin Record Low

Chisos Basin Mean Precip.

January 68.2 90 36.9 -3 0.68”

February 74.4 97 39.1 1 0.58”

March 82.9 105 44.1 12 0.41” April 91.9 109 51.5 25 0.62” May 99.8 115 58.5 37 1.59”

June 103.4 117 63.3 45 2.21”

July 102.2 115 63.7 53 3.39”

August 101.1 114 62.7 52 3.12”

September 96.3 110 58.6 34 2.48” October 88.5 105 51.9 19 1.51”

November 77.7 99 43.2 13 0.57” December 68.4 90 37.9 4 0.51”

Temperatures are in °F and precipitations are in inches.

VI. PAVEMENT DESIGN INPUTS

The pavement design for TX FTNP BIBE 14(2), 13(5), 11(3) 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 for North & West Entrances 60% Directional Distribution for Chisos Basin & Ross Maxwell 50%

Traffic

Traffic estimates for Chisos Basin Road, Ross Maxwell Road, North Entrance Road, and West Entrance Road are based on the National Park Service 2004 Traffic Data Report for Big Bend National Park, adjusted for the increased visitation between 2004 and 2017.

The National Park Service (NPS) website shows a 23% increase in visitation between

2004 and 2017. The 2004 report also provides vehicle distributions for both the north and west entrances. The NPS traffic data is provided in Appendix A and summarized in Table 3 below. The vehicle distribution for both Chisos Basin Road and Ross Maxwell Road is assumed to be an average of the north and west traffic distributions.

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 project’s vehicle classifications in accordance with PDDM Exhibit 11.2-A: 0.004 for Class 2-3, 0.5 for Class5, and 1.0 for Class 4 & 6. Based upon the design criteria and assumptions provided above and the 1993 AASHTO pavement design procedure, the project’s 20-year-18-kip equivalent single axle loads (ESALs) are calculated for the various roads as summarized in Table 3 below (see Appendix D for detailed calculations). According to PDDM Section 11.2.1.2, a minimum of 50,000 ESALs shall be used for the design of paved roads.

Table 3. Big Bend National Park Traffic Data & ESALs

North Entrance West Entrance Chisos Basin / Ross Maxwell

AADT (vehicles/day) 200 250 450 /150 Class 2-3 Cars & Pickups 90% 94% 92%

Class 5 Trucks 7% 5% 6% Class 6 Trucks & Buses 3% 1% 2%

18-kip ESALs 73,006 51,562 107,114 /50,000

Subgrade Soil Resilient Modulus

Thirteen subgrade soil samples were submitted to the CFLHD laboratory to determine their respective R-Values (resistance values on a scale of 0 to 100 per AASHTO T 190).

The lean and fat clays from the North Entrance Road, West Entrance Road, and Ross Maxwell Road were found to have an R-Value less than 5. The clayey sands and gravels from Chisos Basin Road (Borings B-5 through B-11) were found to have a representative R-Value of 21. For silts and clays, the subgrade Resilient Modulus (MR) is calculated from the R-Value using the following correlation equation for fine grained soils from the AGDPS, Page I-14, Equation 1.5.3, MR (psi) = 1,000 + 555 x (R-Value). Based upon an R-Value of 5, the lean and fat clays have a calculated resilient modulus of 3,775 psi. 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

Based upon an R-Value of 21, the Chisos Basin clayey sands and gravel have a calculated resilient modulus of 5,100 psi.

Structural Layer Coefficients

Standard CFLHD structural layer coefficients were selected for asphalt concrete pavement (0.44), crushed aggregate base and full depth reclamation (0.12), and select borrow material (0.06) 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 TX FTNP BIBE 14(2), 13(5), 11(3) project based upon the ESALs, the subgrade Resilient Moduli, and the aforementioned design criteria. The following required 20-year pavement design structural numbers are calculated for the project’s various roads (see Appendix D for calculations).

Required SN for Chisos Basin Rd, Ross Maxwell Rd, & West Entrance Rd = 2.48”

Required SN for North Entrance Road = 2.61”

VII. PAVEMENT RECOMMENDATIONS & DISCUSSION

Project Recommendations

In accordance with the 1993 AASHTO design procedure, a 20-year pavement design requires a Structural Number (SN) of 2.61 for the North Entrance Road and 2.48 for the Chisos Basin Road, Ross Maxwell Road, and West Entrance Road. After evaluating alternatives, the following pavement structural sections are recommended for the project’s five road sections.

North Entrance Road (Route 11) Repair at Milepost 24.8 Raise road with borrow material and subex clays for buffer from expansive soils

4 inches of Asphalt Concrete Pavement (SN = 4” x 0.44 = 1.76”) 8 inches of Crushed Aggregate Base (SN = 8” x 0.12 = 0.96”)

TOTAL SN = 2.72 inches

Chisos Basin Road (Route 14), Southern 2 Miles Only

4 inches of Asphalt Concrete Pavement (SN = 4” x 0.44 = 1.76”) 6 inch FDR – Pulverize Existing Pavement and Base (SN = 6” x 0.12 = 0.72”)

TOTAL SN = 2.48 inches

Ross Maxwell Road (Route 15) Repairs Existing asphalt to be removed

4 inches of Asphalt Concrete Pavement (SN = 4” x 0.44 = 1.76”) 12 inches of Existing Gravel Material (SN = 12” x 0.06 = 0.72”)

TOTAL SN = 2.48 inches

West Entrance Road (Route 13) Repair at Milepost 14.5 Existing asphalt to be removed

4 inches of Asphalt Concrete Pavement (SN = 4” x 0.44 = 1.76”) 12 inches of Existing Gravel Material (SN = 12” x 0.06 = 0.72”)

TOTAL SN = 2.48 inches

West Entrance Road (Route 13) between Mileposts 21.75 and 22.65

4 inches of Asphalt Concrete Pavement (SN = 4” x 0.44 = 1.76”) 6 inch FDR – Pulverize Existing Pavement and Base (SN = 6” x 0.12 = 0.72”)

TOTAL SN = 2.48 inches

The recommended pavement rehabilitation and repairs are not intended to mitigate or prevent future pavement damage from the swelling of the underlying expansive clay soils. Preventing pavement damage from expansive soils would be impractical and uneconomical as previously described.

VIII. MATERIALS RECOMMENDATIONS, SCRs, AND

CONSTRUCTION CONSIDERATIONS

Selection of Asphalt Binder

The TXDOT binder spreadsheet was utilized for the selection of the asphalt binder for the project (See Appendix E). A PG 70-22 binder is recommended for the project’s asphalt pavement. This binder grade is readily available and commonly used by the Texas DOT.

The project was discussed with TXDOT’s Area Engineer, Chris Weber (Alpine, Texas).

Chris Weber indicated that TXDOT almost always uses a PG 70-22 binder for the area’s asphalt pavement.

Pavement Roughness

It is recommended that pavement roughness be evaluated as Type III-A in accordance with SCR Subsection 401.16(d) and Table 401-5. The pavement roughness should be measured for both the top two pavement surfaces with corrections to the lower surface, if necessary. No grinding is allowed on the final pavement surface.

Prime and Tack Coat, 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.

Materials for Culvert Pipe / Cement

Previous pavement reports for Big Bend NP have documented highly corrosive soils. It is recommended that proposed culverts be either plastic pipe, concrete pipe with Type V cement, or be backfilled with non-corrosive soils.

SCRs and Construction Concerns

CFLHD standard SCRs related to pavements and materials are expected to be used for the project. Any additional SCRs may be developed as needed. SCR Subsection 204.07 Subexcavation should stipulate that “prior to backfilling, maintain subgrade at existing moisture content”. SCR Sections 601 and 609 should stipulate that “all minor concrete to include reinforcing fibers and Type V cement (high sulfate resistance).

Bid Items

Suggested FP-14 pay items for the proposed structural section are shown in Table 4 on the following page.

Table 4: Recommended Pay Items Item

Number Item Description Unit Remarks.

20402-0000 Subexcavation CUYD 30202-2000 Roadway Aggregate, Method 2 TON 30401-5300 Full Depth Reclamation, Method 2, 6-Inch Depth MILE

40101-5600 Asphalt Concrete Pavement, Gyratory Mix, 1/2- Inch or 3/4-Inch Nominal Maximum Size Aggregate, 0.3 To <3 Million ESAL

TON

40105-3000 Antistrip Additive, Type 3 TON 40601-0000 Fog Seal TON 41102-1000 Prime Coat, Method 1 SQYD 41105-0000 Blotter TON 41201-0000 Tack Coat TON

APPENDICES

A – Vicinity Map & Traffic Data

B – Boring Log and Lab Report

C – Site Investigation Photos

D – Pavement Design Calculations

E – Asphalt Binder Selection & Climate Data

TX FTNP BIBE 14(2), 13(5), 11(3) Chisos Basin Road and West and North Entrance Roads

APPENDIX A – Vicinity Map & Traffic Data

Vicinity Map

National Park Service 2004 Traffic Data Report

10 0 10 20 Miles

N

EW

S

Big Bend National Park

Texas U.S. Department of Interior

NATIONAL PARK SERVICE

AADT Scale

Traffic Counts

235232

271 91

CASTOLON

OLD M

AVERICK

WEST

ENTRANCE

THE BASIN

GRANDE RD.

BOQUILLAS

N O

RT

H

E N

TR

A

N C

E R

O A

D

GRANDE RIVER

RIO

R O

A D

Reference Station Number in ITALICS

56010

56115613

5614 5616

BIBE-2

National Park Service 2004 Traffic Data Report

BIG BEND NATIONAL PARK 2004 TRAFFIC COMPOSITION SUMMARY

Vehicle Classification Vehicle Occupancy

Location: STATION 56010 Location: STATION 56010

Location: STATION 5620 Location: STAT 5620

CLASSIFICATION LEGEND: OCCUPANCY LEGEND:

No. Vehicle Type FHWA Class No.

M Motorcycles Class 1 1 PC Passenger Cars Class 2 2 RV Recreational Vehicles N/A 3-6 V+T Vehicles/RV pulling Trailer N/A 6+ BUS Transit/Shuttle Buses Class 4 Bus 0 TOUR Tour Buses Class 4 Bus + LT Light-duty Trucks Classes 3, 5 Bus++ HT Heavy-duty Trucks Classes 6 - 13 Bus Full

Note: Vehicle Classifications and Vehicle Occupancy values represented by 0% (No Occurrence) are not shown on the charts.

Vehicle Occupancy

1 Occupant 2 Occupants 3-6 Occupants (car load)

Bus, Fully Loaded

More than 6 Occupants, (non-Bus) Bus, No Passengers Bus, Few Passengers Bus, Semi-Loaded

ION

PC

67.12%

M 2.28%

RV

7.31%

V+T 15.53%

BUS

0.46%

LT

7.31%

6+ 0.91%

3-6 19.18%

Bus Full 0.46% 1

18.72%

60.73%

PC

80.58%

M 3.40%

RV

2.91%

V+T 5.83%

LT

7.28%

66.50%

20.39%

3-6 13.11%

BIBE-5

APPENDIX B – Boring Log and Lab Report

Sample

Number

Station or

Location

Offset

(from c/l)

Date

Sampled

Depth of

Bore Sample Type

Subgrade Related Distress and Requested Testing

0 to 4" Block cracking

4" to 1'

1' to 8' 5 gallon bucket Classification & R-Value

8' to 10'

0 to 3" Wheelpath rutting

3" to 8"

8" to 5' 5 gallon bucket Classification & R-Value

0 to 3" Heave with cracks

3" to 2'

2' to 10'

0 to 3" Minor settlement

3" to 5'

0 to 4" Transverse & block cracks

4" to 1'

1' to 5' 5 gallon bucket Classification & R-Value

0 to 4" Longitudinal cracks &

4" to 1.5' utility trench patch

1.5' to 16' 5 gallon bucket Classification & R-Value

16' to 20'

0 to 4" Transverse & block cracks

4" to 5' 5 gallon bucket Classification & R-Value

0 to 4" Utility trench patch

4" to 5' 5 gallon bucket Classification & R-Value

0 to 3" Transverse cracks &

3" to 7" utility trench patch

7" to 5' 5 gallon bucket Classification & R-Value 0 to 4" Utility trench patch 4" to 5' 5 gallon bucket Classification 0 to 5" Transverse cracks & 5" to 5' utility trench patch 0 to 4" Transverse cracks & 4" to 5' utility trench patch 0 to 4" Transverse cracks & 4" to 5' utility trench patch 0 to 4" Transverse cracks 4" to 5' 5 gallon bucket Classification 0 to 5" Transverse cracks & 5" to 5' utility trench patch 0 to 4.5" Transverse cracks & 4.5" to 5' utility trench patch 0 to 4" Transverse cracks & 4" to 5' utility trench patch 0 to 4" Transverse cracks 4" to 5' 5 gallon bucket Classification 0 to 3" Block cracks 3" to 5'

0 to 4" Heave

4" to 2.5'

2.5' to 8' 5 gallon bucket Classification & R-Value

8' to 10'

0 to 5" Heave & transverse cracks

5" to 2.5'

2.5' to 4'

4' to 8'

8' to 10'

0 to 5" Heave

5" to 1.5'

1.5' to 4' 5 gallon bucket Classification & R-Value

4' to 8'

8' to 10'

0 to 3.5" Heave with cracks

3.5" to 3'

3' to 6'

6' to 10' 5 gallon bucket Classification & R-Value

0 to 4" Heave & transverse cracks

4" to 4'

4' to 7' 5 gallon bucket Classification & R-Value

7' to 10' 5 gallon bucket Classification & R-Value

0 to 4" Longitudinal cracks

4" to 2'

2' to 6'

6' to 8'

8' to 10'

0 to 4" Transverse cracks

4" to 1.3'

1.3' to 10'

0 to 3" Transverse & block cracks

3" to 2'

2' to 5'

0 to 3" Block cracks

3" to 1.5'

1.5' to 5' 5 gallon bucket Classification & R-Value

BIG BEND NATIONAL PARK BORING LOG (May 9-10, 2018)

B-31 West Entrance

MP 22.4

5'LT 5/9/2018 5'

asphalt crushed aggregate base tan clay, dry asphalt tan gravel, dry gray clay, damp tan clay, damp

B-29 West Entrance

MP 21.95

6'LT 5/9/2018 10'

red clay, damp

B-28 West Entrance

MP 21.7

6'RT 5/9/2018 10'

B-32 West Entrance

MP 22.6

5'RT 5/9/2018 5'

asphalt crushed aggregate base tan clay, dry

B-30 West Entrance

MP 22.2

6'RT 5/9/2018 10'

asphalt crushed aggregate base tan clay, dry asphalt tan gravel, dry red clay, damp gray clay, damp

B-27 West Entrance

MP 14.5

6'LT 5/9/2018 10'

asphalt tan gravel, dry reddish gray clay, damp red clay, damp

6'LT 5/9/2018 10'

asphalt brown gravel, dry red clay, dry light gray clay, damp reddish gray clay, damp

B-26 Ross Maxwell

MP 16.5

8'RT 5/9/2018 10'

asphalt brown gravel, dry red clay, dry tan clay, dry red clay, dry

B-2 North Entrance

MP 24.75

3'LT 5/10/2018 5'

asphalt tan clay, moist red clay, damp crushed aggregate base

B-23 Chisos Basin

MP 0.2 Pullout

85'RT 5/10/2018 5'

asphalt tan gravel, dry

B-13 Chisos Basin

MP 4.7

5'LT 5/10/2018 5'

tan gravel, dry

B-24 Ross Maxwell

MP 14.24

asphalt asphalt tan gravel, dry tan gravel, dry

Boring Observations (grey = sample taken ) red clayey sand, damp tan clay, moist asphalt crushed aggregate base crushed aggregate base tan clay, dry tan gravel, dry

7'RT 5/9/2018 10'

asphalt brown gravel, dry light gray clay, damp

B-25 Ross Maxwell

MP 14.26

B-10 Chisos Basin

MP 5.35

5'LT 5/10/2018 5'

B-11 Chisos Basin

MP 5.1

5'LT 5/10/2018 5'

Chisos Basin

MP 4.2

5'LT 5/10/2018 5'

B-16 Chisos Basin

MP 3.8

reddish tan clayey gravel, damp crushed aggregate base reddish tan clayey sand, damp asphalt tan gravel, dry asphalt reddish tan clayey gravel, dry asphalt red clayey sand, damp asphalt tan gravel, dry asphalt tan gravel, dry asphalt tan gravel, dry asphalt tan gravel, dry asphalt tan gravel, dry asphalt asphalt tan gravel, dry asphalt tan gravel, dry

5/10/20185'RT

North Entrance

MP 24.8

B-1 10' asphalt

B-7 Chisos Basin

MP 5.95

6'LT 5/10/2018 20'

asphalt reddish tan gravel, damp

B-5 Chisos Basin

MP 6.25

5/10/2018 crushed aggregate base asphalt

10'5/10/20187'LT

North Entrance

MP 24.7

B-3

B-4

2'RT 5/10/2018 5'

B-15

North Entrance

MP 24.65

5.5'RT 5/10/2018 5'

B-8 Chisos Basin

MP 5.8

3'RT 5/10/2018 5'

6'LT 5'

B-17 Chisos Basin

MP 3.2

5'LT 5/10/2018 5'

B-18 Chisos Basin

MP 2.7

5'RT 5/10/2018 5'

B-19 Chisos Basin

MP 2.25

5'LT 5/9/2018 5'

B-20 Chisos Basin

MP 1.65

5'RT 5/9/2018 5'

B-22 Chisos Basin

MP 0.75

4'RT 5/9/2018 5'

B-21 Chisos Basin

MP 1.25

5'LT 5/9/2018 5'

APPENDIX C – Site Investigation Photos

Boring B-1 at North Entrance Rd MP 24.8, Block Cracking, Looking North

Boring B-1 at North Entrance Rd MP 24.8, Gravel Cuttings

Boring B-2 at North Entrance Rd MP 24.75, 1.5” Deep Wheel Path Rutting

Boring B-3 at North Entrance Rd MP 24.7, Looking North to Boring B-2

Boring B-3 at North Entrance Rd MP 24.7, Road Conditions Looking South

Boring B-3 at North Entrance Rd MP 24.7, Tan Clay Cuttings

Boring B-5 at Chisos Basin Rd MP 6.25, Longitudinal Cracking, Looking South

Boring B-6 at Chisos Basin Rd MP 6.1, Block Cracking, Looking West

Boring B-7 at Chisos Basin Rd MP 5.95, Longitudinal Cracking, Looking South

Boring B-8 at Chisos Basin Rd MP 5.8, Block Cracking, Looking South

Boring B-10 at Chisos Basin Rd MP 5.35, Block Cracking, Looking North

Boring B-11 at Chisos Basin Rd MP 5.1, Block Cracking, Looking North

Boring B-15 at Chisos Basin Rd MP 4.2, Road Conditions Looking South

Boring B-15 at Chisos Basin Rd MP 4.2, Boring Hole with Gravel Cuttings

Boring B-16 at Chisos Basin Rd MP 3.8, Gravel Cuttings

Boring B-17 at Chisos Basin Rd MP 3.2, Road Conditions Looking South

Boring B-20 at Chisos Basin Rd MP 1.65, Gravel Cuttings

Boring B-24 at Chisos Basin Rd MP 0.2, Block Cracking at Pullout, Looking South

Boring B-24 at Ross Maxwell Rd MP 14.24, Looking South to Boring B-25

Boring B-24 at Ross Maxwell Rd MP 14.24, Light Grey Clay Sample

Boring B-25 at Ross Maxwell Rd MP 14.26, Looking North to Boring B-24

Boring B-26 at Ross Maxwell Rd MP 16.5, Road Conditions Looking North

Boring B-27 at West Entrance Rd MP 14.5, Looking West at Heave in Pavement

Boring B-27 at West Entrance Rd MP 14.5, Concrete Ditch Damage at Heave

Boring B-28 at West Entrance Rd MP 21.7, Looking East at Heave in Pavement

Boring B-28 at West Entrance Rd MP 21.7, Boring with Tan Gravel above Red Clay

Boring B-29 at West Entrance Rd MP 21.95, Longitudinal Cracking & Heave

Boring B-29 at West Entrance Rd MP 21.95, Cuttings of Grey and Red Clay

Boring B-30 at West Entrance Rd MP 22.2, Road Conditions Looking East

Boring B-32 at West Entrance Rd MP 22.6, Block Cracking, Looking North

APPENDIX D – Pavement Design Calculations

ESAL Calculations

Project: TX FTNP BIBE 14(2), 13(5), 11(3) - Big Bend National Park Date: 9/27/2018

Location: Brewster County, Texas

North Entrance Road

Performance Period (years) 20

Two-Way Traffic (ADT) 200

Number of Lanes in Design Direction 1

Percent of Trucks in Design Lane 100%

Percent of Trucks in Design Direction 60%

Accumulated

Average Initial 18-kip ESALs for

Vehicle Percent Annual % Growth Truck Factor Performance

Class of ADT Growth Factor (ESALs/Truck) Period

2-3 90% 2% 24.30 0.004 3,831

5 7% 2% 24.30 0.5 37,248

6 3% 2% 24.30 1 31,927

Total 73,006

West Entrance Road

Performance Period (years) 20

Two-Way Traffic (ADT) 250

Number of Lanes in Design Direction 1

Percent of Trucks in Design Lane 100%

Percent of Trucks in Design Direction 60%

Accumulated

Average Initial 18-kip ESALs for

Vehicle Percent Annual % Growth Truck Factor Performance

Class of ADT Growth Factor (ESALs/Truck) Period

2-3 94% 2% 24.30 0.004 5,002

5 5% 2% 24.30 0.5 33,257

6 1% 2% 24.30 1 13,303

Total 51,562

ESAL Calculations (Cont)

Project: TX FTNP BIBE 14(2), 13(5), 11(3) - Big Bend National Park Date: 9/27/2018

Location: Brewster County, Texas

Chisos Basin Road

Performance Period (years) 20

Two-Way Traffic (ADT) 450

Number of Lanes in Design Direction 1

Percent of Trucks in Design Lane 100%

Percent of Trucks in Design Direction 50%

Accumulated

Average Initial 18-kip ESALs for

Vehicle Percent Annual % Growth Truck Factor Performance

Class of ADT Growth Factor (ESALs/Truck) Period

2-3 92% 2% 24.30 0.004 7,343

5 6% 2% 24.30 0.5 59,863

6 2% 2% 24.30 1 39,908

Total 107,114

Ross Maxwell Road

Performance Period (years) 20

Two-Way Traffic (ADT) 150

Number of Lanes in Design Direction 1

Percent of Trucks in Design Lane 100%

Percent of Trucks in Design Direction 50%

Accumulated

Average Initial 18-kip ESALs for

Vehicle Percent Annual % Growth Truck Factor Performance

Class of ADT Growth Factor (ESALs/Truck) Period

2-3 92% 2% 24.30 0.004 2,448

5 6% 2% 24.30 0.5 19,954

6 2% 2% 24.30 1 13,303

Total 35,705

Design ESALs 50,000

APPENDIX E – Asphalt Binder Selection & Climate Data

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