CO_FLAP_102(1)_Brainard_Lake_Road_Pavements_Report_2-25-2015.pdf

ARAPAHOE & ROOSEVELT National Forest

CO FLAP 102(1) BRAINARD LAKE ROAD

PAVEMENT REPORT

Report # 15-01

CO FLAP 102(1) Brainard Lake Road iii

TABLE OF CONTENTS

I. INTRODUCTION

II. CLIMATE

III. EXPLORATION

IV. EXISTING PAVEMENT & SOILS

V. PAVEMENT DESIGN CALCULATION INPUTS

VI. PAVEMENT RECOMMENDATIONS & DISCUSSION

VII. MATERIALS RECOMMENDATIONS

APPENDICES

A – Location Map B – Laboratory Reports and Boring Log C – Photographs D – DARWin Pavement Design E – PG LTPPBIND Software F – Weather Data Information G – Preliminary Pavement Recommendation Memo H – Culvert Pipe Selection Criteria

I. INTRODUCTION

This report is written to document road conditions for the planned 2016/2017 CO FLAP 102(1) Brainard Lake Road project. The project is located approximately 20 miles northwest of Boulder, Colorado within the Boulder District of the Arapahoe & Roosevelt National Forests. On November 17, 2014, a pavement and subgrade soil investigation was conducted. The investigation began at the intersection of Brainard Lake Road and the Peak to Peak highway (CO 72) and concluded approximately 2.5 miles from the intersection, connecting with the CO PFH 112-1(1) Brainard Lake Road project, constructed in 2010 and 2011. The Preliminary Pavement Recommendations Memo was issued in December of 2014. The memo provided the pavement recommendations as well as the proposed pay items. This memo is found in the Appendix. The pavement recommendations have been finalized and are discussed in Part VI of this report.

II. CLIMATE

Climate data was obtained from intellicast.com. This data is summarized in Table 1 below and is shown in the Appendix. The average precipitation for this area is approximately 20.75 inches. The project is located at an elevation that receives both snow and rain, dependent upon the time of year. The project ranges in elevation from ≈9,250 feet to ≈10,000 feet.

TABLE 1: Weather Data

Month Average

HIGH

Record

HIGH

Average

LOW

Record

LOW

Average

PRECIP.

January 32 53 4 -43 1.83

February 36 56 6 -40 1.51

March 42 67 13 -30 1.52

April 50 74 20 -19 1.96

May 60 82 28 4 2.05

June 71 89 34 16 1.49

July 76 92 39 21 2.11

August 74 92 38 18 2.15

September 68 89 31 7 1.68

October 57 76 23 -8 1.50

November 40 68 13 -28 1.37

December 32 54 5 -35 1.58

Temperatures are in °F and precipitations are in inches.

III. EXPLORATION

A pavement and subgrade soil investigation was performed on November 17, 2014. Prior to the investigation, CFL made a separate trip to mark proposed pavement borings. CFL also called 811 for utility locations prior to the investigation. The pavement and subgrade investigation used a truck mounted drill rig, CME 55 by Vine Laboratories, Inc. of Denver, CO, to auger through the existing pavement and to continue into the subgrade from 1 foot to 5 feet in depth. CFL personnel logged the borings; this included depth of boring, visual soil classification, pavement thickness, pavement distress, and road width.

Boring locations, paved widths and other information is shown in the Appendix.

IV. EXISTING PAVEMENT & SOILS

The existing pavement was drilled at 0.10-mile to 0.50-mile increments, with boring locations alternating between lanes. The results of the visual classification can be found in the Appendix. A visual presentation of the layers observed is shown in Figure 1. The existing roadway was found to be in poor condition based on the transverse, longitudinal and alligator cracking present as well as noticeable rutting.

In general, pavement thickness ranged from 4.50 inches to 7.0 inches, with the majority being over 6.0 inches. Multiple layers of pavement appeared to be present. Generally speaking, the underlying subgrade appeared to stay consistent through the project limits.

No distinct aggregate base layer was found during the investigation. However, the subgrade material below the pavement is of good quality. The subgrade soils were classified as A-1-b and A-2-4 with low plasticity. See the laboratory reports in the Appendix for more information.

Drilling efforts ranged from easy to difficult, with the more difficult locations higher in elevation. Four boring locations hit refusal within the top 3 feet. A second boring was taken immediately adjacent to these locations in order to obtain bulk samples as well as obtain a 5 foot depth. Note that borings 5 and 6 were unable to reach 5 feet.

B‐9, S‐1, M.P. 0.05

B‐1, S‐2, M.P. 0.40

B‐10, S‐3, M.P. 0.60

B‐2, S‐4, M.P. 0.90

B‐3, S‐5, M.P. 1.20

B‐4, S‐6, M.P. 1.50

B‐5, S‐7, M.P. 1.90

B‐6, S‐8, M.P. 2.00

B‐7, S‐9, M.P. 2.10

B‐8, S‐10, M.P. 2.40

Ex p lo ra to ry D e p th In ch e s)

Brainard Lake Road Visual Classification of Boring Logs

Existing Pavement Existing Granular Subgrade

Figure 1: Brainard Lake Road Visual Classification of Boring Locations

V. PAVEMENT DESIGN CALCULATION INPUTS

Design Parameters

The traffic count used for the pavement design was obtained from the 30% design package. An average daily traffic (ADT) of 620 was used, resulting in a calculated cumulative equivalent single axel load (ESALs) of 58,856 for a 25 year period. The assumptions made in the ESAL calculations as well as related design factors are included in the Appendix. Design factors used in the ESALs calculations as well as the structural coefficients were taken from the CFLHD Project Development Design Manual (PDDM), Chapter 11.

Roadbed Soil Resilient Modulus

The soil resilient modulus shown in Table 2 below was converted from R-Value, AASHTO T 190, using the following equation:

Resilient Modulus (psi) = 10[ ( S

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

Table 2 R-Value to Resilient Modulus

Section R-Value Resilient Modulus Station 110+00, M.P. 0.60, LT, Boring 10 64 20,797 psi Station 62+50, M.P. 1.50, RT, Boring 4 74 28,840 psi Station 28+00, M.P. 2.10, LT, Boring 7 56 15,848 psi Design Value Used 16,000 psi Stationing based on 30% design package

VI. PAVEMENT RECOMMENDATIONS & DISCUSSION

Utilizing the DARWin Pavement Design and Analysis System, a 25 year pavement design required a Calculated Design Structural Number (SN) of 1.45. After evaluating various alternatives and performing various iterations, the following is the recommended pavement structural section:

3.0 inches HACP, placed in two lifts (entire proposed width, Section 401)

8.0 inches FDR – Pulverize (existing roadway, Section 304) Minor Crushed Aggregate (widening & shouldering, Section 302)

SN = 1.84

VII. MATERIALS RECOMMENDATIONS

Selection of Asphalt Binder

LTPPBind software was utilized to assist in the selection of asphalt binder. The information presented in LTPPBind is shown in the Appendix. LTPPBind indicated that a PG 46-28 should be used. However, this PG binder is not commonly produced. In addition, LTPPBind did not have weather stations close in either elevation or proximity to the project location. Consideration was given to the location of the project as well as performance of past projects in similar conditions.

Based on these considerations, a PG 58-34 was selected. This binder grade is used by the Colorado Department of Transportation (CDOT). The binder appears to be available at several refineries in the area Prime and Tack Coats, Blotter and Fog Seal

Prime Coat and Blotter are not required for this project. A tack coat applied between pavement lifts is recommended. It is also recommended that a fog seal be applied to the final surfacing.

Drainage and Subexcavation

During the field investigation, areas of pavement distress were present. However, they appeared to be caused due to fatigue and age. No major water damage or drainage problems pertaining to the existing traveled way were observed. Should any drainage issues exist, the scope of the project allows for partial reconstruction. As of the 30% submittal, a quantity of 500 tons of subexcavation is shown in the Contract. This quantity should remain in the Contract in the event that areas in need of repair are encountered.

Culvert Materials

Testing showed pH levels ranging from a 5.7 to a 6.0, with resistivity from 9,950 to 19,890 ohm-cm. After reviewing this information and using the selection criteria shown in the Appendix, the soil is considered non corrosive, and no special materials are needed.

Bid Items

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

Table 3: Recommended Pay Items Item

Number Item Description Unit Remarks.

30202-2000 Minor Crushed Aggregate, Method 2 TON

30401-1500 Full Depth Reclamation, Method 1, 8-Inch Depth Mile

40101-5600

Asphalt Concrete Pavement, Gyratory Mix, ½-Inch or ¾-Inch

Nominal Maximum Size Aggregate,

0.3 To <0.3 Million ESAL

TON

40601-0000 Fog Seal TON 41201-0000 Tack Coat TON

APPENDICES

A – Location Map

B – Laboratory Reports and Boring Log

C – Photographs

D – DARWin Pavement Design

E – PG LTPPBind Software

F – Weather Data Information

G – Preliminary Pavement Recommendation Memo

H – Culvert Pipe Selection Criteria

APPENDIX A – Location Map

APPENDIX B – Laboratory Reports and Boring Log

Project:

Sample

Number

Station or

Location Offset

Date

Sampled

Depth of

Bore

Container

Type

0'‐0" to 0'‐7"

0'‐0" to 0'‐6.5"

0'‐0"‐0'‐7.5"

0'‐0" to 0'‐5"

0'‐5" to 5'‐0"

0'‐0" to 0'‐7"

0'‐0" to 0'‐6"

CO FLAP 102(1) Brainard Lake Road & Bridge 510.PE.G20E 1608000000 15X0G20050 510 PEAccount Number:

Submitted By: Date Submitted: 19‐Nov‐14Sampled By:Jeff Felling Felling / Voth

HACP

1,2,3

1,2,3,4

HACP

Similar to previous borings. Top 2‐1/2' moist, some PI. Uniform material from bottom of AC ‐ 5', bottom 2' dry. Easy drilling.

1,2,3

Boring Observations

1,2,311/17/2014RT

B‐9 @ MP

0.05 S‐1 5'‐0"

5‐Gallon bucket

Testing Requested

HACP

HACP

1,2,3,4,16,17, AASHTO

T 290/291 Sulfates and

Chlorides

S‐4

B‐2 @ MP

0.90

RT 11/17/2014 5'‐0"

5‐Gallon bucket

B‐10 @ MP

0.60

S‐3 LT 11/17/2014 5'‐0"

5‐Gallon bucket

HACP

5‐Gallon bucket

5'‐0"11/17/2014LT

B‐1 @ MP

0.40 S‐2 1,2,3

HACP

S‐6

B‐4 @ MP

1.50

RT 11/17/2014 5'‐0"

5‐Gallon bucket

S‐5

B‐3 @ MP

1.20

11/17/2014LT 5'‐0"

5‐Gallon bucket

Investigation Sampling & Request for Laboratory Tests

0'‐7" to 5'‐0"

Some 3/4" rock, from bottom of AC to 2‐1/2' ‐

3' was moist, some PI., 3'‐5' same material, dry, no PI. Brown, yellowish‐orange. Medium drilling effort.

0'‐6.5" to 5'‐0"

Similar material to B‐9. Dark brown, moist

3/4" minus finer material, some PI in top 2‐

1/2'. From 3'‐5' similar to B‐9, dry yellowish orange. Easy Drilling.

Similar to previous borings. Top 2‐1/2' moist, some PI. Uniform material from bottom of AC ‐ 5', bottom 2' dry. Easy drilling.

0'‐7.5" to 5'‐0"

Similar to previous borings. Top 2‐1/2' moist, some PI. Uniform material from bottom of AC ‐ 5', bottom 2' dry. Easy drilling.

0'‐7" to 5'‐0"

0'‐6" to 5'‐0"

Similar to previous borings. Top 2‐1/2' moist, some PI. Uniform material from bottom of AC ‐ 5', bottom 2' dry. Some frozen clay found. Easy drilling.

Project:

Sample

Number

Station or

Location Offset

Date

Sampled

Depth of

Bore

Container

Type

O'‐0" to 0'‐6.5"

0'‐0" to 0'‐4.5"

0'‐0" to 0'‐6.5"

0'‐0" to 0'‐6.5"

Note: There was a noticeable 1‐1/2" overlay noted when examining pavement depths at the boring locations.

No cores were taken on this project. Project is 4R with heavy excavation.

No borings were taken at the bridge site per geotechs direction.

Filepath: N:\CO\102(1)\Pavements\1. Investigation‐Analysis‐Design

HACP

1,2,3

1,2,3

Similar material, brown, with frozen clay, some small stone. Drill hit refusal at 18" hard drilling.

2nd boring taken immediately adjacent, similar material, able to drill to 5'. Material from both borings combined to make bulk sample.

HACP

1,2,3,4,16,17, AASHTO

T 290/291 Sulfates and

Chlorides

HACP

Not Sampled. No testing requested.

Date Submitted: 19‐Nov‐14

Boring Observations Testing Requested

RT 11/17/2014 5'‐0"

5‐Gallon bucket

B‐7 @ MP

2.10

LT

0'‐6.5" to 5'‐0"

11/17/2014 5'‐0" 5‐Gallon bucket

HACP

S‐7

B‐5 @ MP

1.90

LT

S‐8

B‐6 @ MP

2.00

RT 11/17/2014 5'‐0"

5‐Gallon bucket

11/17/2014 5'‐0" 5‐Gallon bucket

S‐9

S‐10

B‐8 @ MP

2.40

0'‐6.5" to 5'‐0"

Similar to previous borings. Top 2‐1/2' moist, dark brown. 1st boring hit refusal at

3'. 2nd boring taken immediately adjacent, able to drill to 5'. Similar material to other borings. Both borings combined to make bulk sample.

Similar material as other borings.

Encountered bolder w/ drilling refusal at

24".

0'4.5" to 2'‐0"

0'‐6.5" to 1'‐6"

Similar material as other borings.

Encountered bolder w/ drilling refusal at

18".

Investigation Sampling & Request for Laboratory Tests

CO FLAP 102(1) Brainard Lake Road & Bridge Account Number: 510.PE.G20E 1608000000 15X0G20050 510 PE

Submitted By: Jeff Felling Sampled By: Felling / Voth

APPENDIX C – Photographs

Pre-Investigation Photographs

Typical Roadway Cross Section

Typical Existing Rutting, Alligator and Transverse Cracking

Typical Thermal Cracking

Typical Pavement Patches

Investigation Photographs

Typical Drilling Conditions

Typical Drilling Conditions

Typical Subgrade Material

Typical Boring(s) and Auger Attachment

APPENDIX D – DARWin Pavement Design

1993 AASHTO Pavement Design

DARWin Pavement Design and Analysis System

A Proprietary AASHTOWare Computer Software Product

Flexible Structural Design Module

Flexible Structural Design

18-kip ESALs Over Initial Performance Period 58,856 Initial Serviceability 4.2 Terminal Serviceability 2.5 Reliability Level 75 % Overall Standard Deviation 0.49 Roadbed Soil Resilient Modulus 16,000 psi Stage Construction 1

Calculated Design Structural Number 1.45 in

Rigorous ESAL Calculation

Performance Period (years) 25 Two-Way Traffic (ADT) 620 Number of Lanes in Design Direction 1 Percent of All Trucks in Design Lane 100 % Percent Trucks in Design Direction 50 %

Vehicle Class

Percent of

ADT

Annual

Growth

Average Initial Truck Factor

(ESALs/ Truck)

Annual % Growth in

Truck Factor

Accumulated 18-kip ESALs over Performance Period

2 99 0 0.0008 0 2,242 10 1 0 2 0 56,614

Total 100 - - - 58,856

Growth Simple

Total Calculated Cumulative ESALs 58,856

Specified Layer Design

Layer

Material Description

Struct Coef.

(Ai)

Drain Coef.

(Mi)

Thickness (Di)(in)

Width

(ft)

Calculated

SN (in) 1 401 Superpave 0.4 1 3 - 1.20 2 304 FDR-Pulverize 0.08 1 8 - 0.64

Total - - - 11.00 - 1.84

APPENDIX E – PG LTPPBIND Software

LTTP Bind Table

APPENDIX F – Weather Data Information

The Authority in Expert Weather

Universal Time: Tuesday, 10 Feb 2015, 00:01

Historic Average Home » Local » Historic Averages

Monthly Averages & Records - °F | °C

Daily Averages & Records - °F | °C

Ward, Colorado Weather Report · Interactive Map · Extended Forecast · Hourly Forecast · Past Observations · Historic Averages

Date Average Low

Average High

Record Low

Record High

Average Precipitation

Average Snow

January 4° 32° -43° (1963) 53° (1986) 1.83" NA

February 6° 36° -40° (1951) 56° (1986) 1.51" NA

March 13° 42° -30° (1965) 67° (1987) 1.52" NA

April 20° 50° -19° (1973) 74° (1975) 1.96" NA

May 28° 60° 4° (1973) 82° (2003) 2.05" NA

June 34° 71° 16° (1978) 89° (1988) 1.49" NA

July 39° 76° 21° (1959) 92° (1978) 2.11" NA

August 38° 74° 18° (1978) 92° (1995) 2.15" NA

September 31° 68° 7° (1961) 89° (1978) 1.68" NA

October 23° 57° -8° (1993) 76° (2003) 1.5" NA

November 13° 40° -28° (1976) 68° (1999) 1.37" NA

December 5° 32° -35° (1990) 54° (1998) 1.58" NA

Date Average Low

Average High

Record Low

Record High

Average Precipitation

Average Snow

Feb 1 4° 34° -40° (1951) 52° (2003) 0.06" NA

Feb 2 4° 34° -34° (1956) 49° (2003) 0.06" NA

Feb 3 4° 34° -28° (1956) 46° (1963) 0.06" NA

Feb 4 4° 34° -23° (1956) 51° (1954) 0.06" NA

Feb 5 4° 34° -22° (1985) 51° (1963) 0.06" NA

Feb 6 4° 34° -35° (1989) 52° (1963) 0.06" NA

Feb 7 4° 35° -30° (1989) 50° (1987) 0.06" NA

Feb 8 5° 35° -25° (1989) 54° (1987) 0.06" NA

Feb 9 5° 35° -25° (1956) 51° (1987) 0.06" NA

Feb 10 5° 35° -25° (1986) 49° (1996) 0.06" NA

Feb 11 5° 35° -30° (1955) 56° (1962) 0.06" NA

Feb 12 5° 36° -24° (1963) 52° (1962) 0.05" NA

Feb 13 5° 36° -20° (1963) 52° (1979) 0.05" NA

Feb 14 5° 36° -23° (1951) 50° (1999) 0.05" NA

Feb 15 6° 36° -22° (1964) 47° (1961) 0.05" NA

Feb 16 6° 36° -22° (1965) 47° (1957) 0.05" NA

Feb 17 6° 37° -17° (1988) 50° (1994) 0.05" NA

Feb 18 6° 37° -24° (1960) 53° (2004) 0.05" NA

Feb 19 6° 37° -20° (1956) 50° (1958) 0.05" NA

Feb 20 7° 37° -21° (1973) 51° (1995) 0.05" NA

Feb 21 7° 38° -30° (1955) 53° (1995) 0.05" NA

Feb 22 7° 38° -28° (1953) 54° (1995) 0.05" NA

Feb 23 7° 38° -24° (1975) 53° (2002) 0.05" NA

Feb 24 8° 38° -25° (1974) 52° (1995) 0.05" NA

Feb 25 8° 38° -30° (1952) 56° (1986) 0.05" NA

Feb 26 8° 39° -31° (1964) 56° (1950) 0.05" NA

Feb 27 8° 39° -15° (1961) 54° (1988) 0.05" NA

Feb 28 9° 39° -37° (1962) 52° (2006) 0.05" NA

Feb 29 9° 39° -22° (1960) 50° (1992) 0.05" NA

Advertisements National News

Advertise with Us Contact Us Account Help NewsAbout Us Ad Choices

Privacy Statement © 2015 Partnered with Terms of Use Weather Underground Version 4.6.201311.1

Enter City, State, Country or U.S. Zip code

Profile Alerts Hurricanes Help iNav

Ward, Colorado

Local Interactive National Global Storms Health Travel Forecast Current Radar Satellite

Page 1 of 1Intellicast - Ward Historic Weather Averages in Colorado (80481)

2/9/2015http://www.intellicast.com/Local/History.aspx?location=USCO0398

APPENDIX G – Preliminary Pavements Memo

APPENDIX H – Culvert Pipe Selection Criteria