TX_FTNP_CHAM_10(1)_Pavements_Report_Signed.pdf

CHAMIZAL NATIONAL MEMORIAL

CIRCLE DRIVE AND PARKING LOT

EL PASO COUNTY, TEXAS

TX FTNP CHAM 10(1)

PAVEMENT AND MATERIALS REPORT

JULY 2018

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 CHAM 10(1) Circle Drive, Chamizal National Memorial iii

TABLE OF CONTENTS

I. INTRODUCTION

II. CLIMATE

III. EXPLORATION

IV. EXISTING PAVEMENT & SOILS

V. PAVEMENT DESIGN INPUTS

VI. PAVEMENT RECOMMENDATIONS & DISCUSSION

VII. MATERIALS RECOMMENDATIONS

APPENDICES

A – Vicinity and Boring Locations Maps 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 CHAM 10(1) project for the rehabilitation of the paved circle drive and parking lot at the Chamizal National Memorial in El Paso County, Texas. The memorial lies immediately west of Interstate 110 and just north of the Mexico border and the Rio Grande River in El Paso, Texas. Vicinity and Boring Locations maps are provided in Appendix A.

II. CLIMATE

Climate data was obtained from the Intellicast.com website for El Paso, Texas. The data is summarized in Table 1 below and provided in Appendix E. The average annual precipitation for this area is approximately 9.5 inches. The project is located at an elevation of 3,700 feet above sea level and receives both snow and rain, depending upon the time of year. The memorial receives approximately 7 inches of snow annually.

Table 1. Weather Data

Month Average

HIGH

Record

HIGH

Average

LOW

Record

LOW

Average

PRECIP.

January 57 80 33 -8 0.45”

February 63 86 38 5 0.39”

March 70 93 44 14 0.26” April 78 98 51 23 0.23”

May 87 105 61 31 0.38”

June 95 114 69 46 0.87”

July 94 112 72 56 1.49”

August 92 110 70 52 1.75”

September 87 104 64 41 1.61” October 78 96 52 25 0.81”

November 66 87 40 1 0.42” December 57 80 33 -5 0.77”

Temperatures are in °F and precipitations are in inches.

III. EXPLORATION

On May 8, 2018, a pavement and subgrade investigation was conducted for the project consisting of eleven shallow borings (1 to 5 foot depth). The locations of the soil borings (B-1 through B-12) are shown on the Boring Locations map in Appendix A. Boring B-8 was not drilled due to the utilities in the area. CFL personnel logged the findings including depth of boring, visual soil classification, pavement thickness, and areas of distress. During the site visit, four subgrade soil samples were collected. Two of these samples were submitted to the CFLHD laboratory for soil classification and R-Value testing. The boring log and laboratory report are provided in Appendix B.

IV. EXISTING PAVEMENT & SOILS

The existing pavement was found to be asphalt concrete pavement in poor condition. The existing asphalt pavement exhibits thermal and block cracking that comes with an old age hardened pavement. The existing pavement section generally consists of 3 inches of asphalt pavement over 6 to 9 inches of crushed aggregate base (9 inch depth along the circle drive and 6 inch depth within the parking lot). In general, the subgrade soils beneath the aggregate base consists of lean clay with sand (ASTM CL soil / AASHTO A- 6(10) soil) over sandy silts (ASTM ML soil / AASHTO A-4(0) soil). The boring log and laboratory report are provided in Appendix B.

V. PAVEMENT DESIGN INPUTS

The pavement design for TX FTNP CHAM 10(1) 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 one lane circle drive) 100%

Traffic

The site includes paved parking lots with 160 public parking spaces and approximately 20 NPS parking spaces, as well as, a gravel overflow lot with more than 100 additional parking spaces. According to the National Park Service website, for 2011 through 2017, the annual recreational visitation to the memorial is approximately 120,000 people with the non-recreational visits being approximately half of the recreational visits, or approximately 60,000 people, for a total of 180,000 annual visitors. Assuming three people per vehicle, this equates to an ADT (average daily traffic) of 160 for the one lane circle drive. The circle drive and parking lots at the Chamizal National Memorial are used for tourism and special events with the vast majority of vehicles being passenger cars, pickups, and SUVs. There are occasional garbage trucks, delivery trucks, RVs, and buses. The vehicle distribution for the site is assumed to be 97% Class 2-3 cars, pickups, and SUVs and 3% Class 4-6 two and three axle RVs, buses, and garbage/delivery 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: 0.004 for Class 2-3 and 1.0 for Class 4-6. 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 48,075 (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

Two subgrade soil samples (lean clay with sand and sandy silt) 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 clay that lies below the existing pavement section was found to have an R-Value of 8. The sandy silt that underlies the clay was significantly stiffer with an R-Value of 53. 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 8, the clay subgrade was calculated to have a Resilient Modulus of 5,440 psi.

Structural Layer Coefficients

Standard CFLHD structural layer coefficients were selected for asphalt concrete pavement (0.44) and crushed aggregate base (0.12) 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 Pavement Interactive App for the 1993 AASHTO pavement design procedure is used to determine the required pavement structural numbers (SN) for the TX FTNP CHAM 10(1) circle drive and parking lot. Based upon the ESALs, the subgrade Resilient Modulus, and the aforementioned design criteria, the following required pavement design structural number is calculated.

Required SN for Chamizal National Memorial = 2.20 inches

VI. PAVEMENT RECOMMENDATIONS & DISCUSSION

Project Recommendations

In accordance with the 1993 AASHTO design procedure, a 20 year pavement design requires a Structural Number (SN) of 2.2. After evaluating alternatives, the following pavement structural section is recommended for the paved drives and parking lot:

3 inches Asphalt Concrete Pavement (SN = 3” x 0.44 = 1.32”) Existing Aggregate Base (9” typical) (SN = 9” x 0.12 = 1.08”)

TOTAL SN = 2.40 inches

Handicap parking stalls to consist of 6 inches of Portland cement concrete over 6 inches of crushed aggregate base. The existing asphalt to be removed by milling. It is recommended that the asphalt millings be recycled for use as aggregate base for the existing gravel lot; to be paid for with the 30203 line item (see below).

VII. MATERIALS RECOMMENDATIONS, SCRs, AND

CONSTRUCTION CONSIDERATIONS

Selection of Asphalt Binder

LTPPBind and the TXDOT binder spreadsheet were 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.

Tack Coat and Fog Seal

A Tack Coat applied between asphalt lifts, and a Fog Seal applied to the final pavement surface are recommended

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 302 Minor Crushed Aggregate;

Section 403 Asphalt Concrete; and Section 703 Aggregate. The 302 and 703 SCRs to provide for the use of recycled asphalt millings as aggregate base. The 403 SCR to provide for a TXDOT asphalt mix. Any additional SCRs may be developed as needed.

Bid Items

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 30202-2000 Roadway Aggregate, Method 2 TON 30203-2000 Roadway Aggregate, Method 2 (Recycled Asphalt Millings) SQYD 30303-1000 Roadbed Reconditioning SQYD 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 41301-0800 Asphalt Pavement Milling, 3-Inch Depth SQYD 50101-0600 Minor Concrete Pavement, Reinforced, 6-Inch Depth SQYD

APPENDICES

A – Vicinity and Boring Locations Maps

B – Boring Log and Lab Report

C – Site Investigation Photos

D – Pavement Design Calculations

E – Asphalt Binder Selection & Climate Data

APPENDIX A – Vicinity & Boring Locations Maps

VICINITY MAP

Boring Locations Legend Chamizal National Memorial Feature 1

500 ft N

N© 2018 Google

© 2018 Google

© 2018 Google

© 2018 INEGI

© 2018 INEGI

© 2018 INEGI

B-11

B-12

APPENDIX B – Boring Log and Lab Report

Sample

Number Location

Date

Sampled

Depth of

Bore Sample Type Requested Testing

0 to 3"

3" to 7"

7" to 2.5'

2.5' to 5'

0 to 3"

3" to 9"

9" to 1.25'

0 to 3"

3" to 9"

9" to 2'

2' to 5'

0 to 3"

3" to 9"

9" to 1.25'

0 to 3"

3" to 1'

1' to 2'

2' to 5' 5 gallon bucket No testing

0 to 3"

3" to 1'

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

2.5' to 5'

0 to 3"

3" to 1'

1' to 1.25'

0 to 3"

3" to 1'

1' to 3'

3' to 5'

0 to 3"

3" to 1'

1' to 3' 5 gallon bucket No testing

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

0 to 6"

6" to 1'

0 to 6"

6" to 1'

West Center Island of Parking Lot B-3

B-4 West End of Parking

Lot 5/8/2018

B-5 West Entrance 5/8/2018 crushed aggregate base asphalt

5'

B-7 South Circle Drive 5/8/2018 1.25' asphalt brown clay, moist tan sand, moist brown clay, moist surface gravel brown clay, dry surface gravel brown clay, dry

5/8/2018 5' asphalt

5'5/8/2018

1.25' tan crushed aggregate base brown clay, moist tan crushed aggregate base brown clay, moist tan crushed aggregate base tan crushed aggregate base asphalt tan sandy gravel brown clay, moist

Boring Observations (grey = sample depth ) tan sand, moist brown clay, moist asphalt tan crushed aggregate base tan crushed aggregate base tan clayey silt, moist brown clay, moist brown clayey sand, moist tan crushed aggregate base brown clayey silt, moist

B-12 Center of North

Gravel Lot 5/8/2018 1'

B-10 North Circle Drive 5/8/2018 5'

B-11 Center of Gravel Lot

Entance 5/8/2018 1' asphalt brown clayey silt, moist

CHAMIZAL NATIONAL MEMORIAL BORING LOG (May 8, 2018)

B-2 East Center Island of

Parking Lot 5/8/2018 1.25' asphalt

East End of

Parking Lot B-1

B-6 West Circle Drive 5/8/2018 5' asphalt tan crushed aggregate base

B-9 East Circle Drive 5/8/2018 5' asphalt tan sand, moist

APPENDIX C – Site Investigation Photos

Typical Block and Thermal Cracking on Loop Road

Typical Block and Thermal Cracking in Parking Lot

Typical Block and Thermal Cracking in Parking Lot near Boring B-3

Crushed Aggregate Base and Brown Clay Subgrade Material at Boring B-2

APPENDIX D – Pavement Design Calculations

Rigorous ESAL Calculation

Project: Chamizal National Memorial Circle Drive & Parking Lot Date: July 2018

Project No: TX FTNP CHAM 10(1)

Location: El Paso County, Texas

Performance Period (years) 20

Circle Drive Traffic (ADT) 160

Number of Lanes in Design Direction 1

Percent of Trucks in Design Lane 100%

Percent of Trucks in Design Direction 100%

Accumulated

Average Initial 18-kip ESALs for

Vehicle Percent Annual % Growth Truck Factor Performance

Class of ADT Growth Factor (ESALs/Truck) Period

2-3 97% 2% 24.30 0.004 5,506

4 - 6 3% 2% 24.30 1 42,569

Total 48,075

Chamizal National Memorial, El Paso, Texas

Pavement Design Structural Number (SN) Calculation

APPENDIX E – Asphalt Binder Selection & Climate Data

LTPPBind V3.1 Data

TXDOT ASPHALT BINDER SELECTION SPREADSHEET

Recommended PG Binder Grade:

Note: This grade is for asphalt paving mixtures!

Location Range:

Maximum High PG Grade: 70 min max Minimum Low PG Grade: ‐22 Long: 106.32 106.60 Minimum High Confidence: 99.33% Lat: 31.70 31.97

Total Number of Stations Used: 3 Minimum Low Confidence: 99.88% Elev: 1119 1196

Station Identity PG Grading Location Information Weather Data

7‐Day 7‐Day 7‐Day Average Low Average High High at Hi Below

State County Station Name High Low Long. Lat. Elevation Low St. Dev. High St. Dev. Surface Surface

TX EL PASO YSLETA 64.2 -18.8 70 ‐22 100.00% 99.88% 106.32 31.70 1119 -12 3.3 39 1.7 64.4 60.7 TX EL PASO EL PASO WSO AP 63.3 -17.8 64 ‐22 99.33% 99.96% 106.40 31.80 1196 -11 3.3 38 1.7 63.4 59.8 TX EL PASO LA TUNA 1 S 64.2 -16.8 70 ‐22 100.00% 100.00% 106.60 31.97 1159 -11 2.8 39 1.7 64.4 60.7

PG 70-22

True Confidence Interval

PG Grade PG Grade Theoretical Recommended

PG Binder SPG Binder

Select New Location

Climate Data

SCFLBRIDGEK18071617030