CFL Dino Harpers Corner_Final Pavement Report_20220329.pdf

SUBMITTED TO:

DJ&A

2000 Maple Street Missoula, Montana, 59808

BY:

Shannon & Wilson 1321 Bannock St., Suite 200 Denver, Colorado 80204

(303) 825-3800 www.shannonwilson.com

PAVEMENT DESIGN REPORT

CO FTNP DINO 11(1)

Harpers Corner Road

MOFFAT COUNTY, COLORADO

March 2022

Shannon & Wilson No: 107616-002

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CONTENTS

1 Introduction

2 Project and Site Description

3 Subsurface Investigation and Laboratory Testing

3.1 Field Investigation

3.2 Geotechnical Laboratory Testing

4 Subsurface Conditions

4.1 Regional Geology

4.2 Existing Pavement Thicknesses

4.3 Pavement Subgrade

4.4 Groundwater

5 Pavement assessment

6 Pavement Design Recommendations

6.1 Design Methodology

6.2 Traffic Loading

6.3 Design Subgrade R-value

6.4 Full Depth Reclamation

6.5 Recommended Pavement Sections

7 Additional Considerations

7.1 Subgrade Failure

7.2 Swelling Soils

7.3 Landslide Area

7.4 Frost Damage

8 Construction and Material Specifications

8.1 Earthwork

8.1.1 General

8.1.2 Subgrade Preparation and Fill Placement

8.1.3 Low Permeable Fill

8.1.4 Proof-Rolling

8.2 Paving Materials

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9 Closures

10 References

Exhibits Exhibit 6-1: Summary of R-value Test Results Exhibit 6-2: Recommended Pavement Sections Exhibit 8-1: Recommended Materials for Pavements

Figures Figure 1: Vicinity Map Figure 2: Site and Exploration Plan

Appendices Appendix A: Subsurface Explorations Appendix B: Laboratory Test Results Appendix C: Photographs Appendix D: Pavement Design Calculations Important Information

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1 INTRODUCTION

This report summarizes the results of our subsurface exploration and laboratory testing program and presents pavement design recommendations and construction considerations for the proposed Harpers Corner Road, CO FTNP DINO 11(1) (the Project) in Moffat County, Colorado. Our scope of services was specified in our Professional Services Agreement with DJ&A dated October 15, 2021. Our conclusions and recommendations in this report are based on:

The limitations of our approved scope, schedule, and budget described in our contract;

Our understanding of the Project and information provided by DJ&A;

Subsurface conditions observed in the borings at the time our explorations were completed; and

The results of testing performed on samples collected from the explorations.

The objective of our geotechnical studies was to provide recommendations and construction considerations, as presented herein, for the proposed roadway reconstruction. The authorized scope of services was based on this objective, and this report should not be used for other purposes without Shannon & Wilson’s review. If a service is not specifically indicated in this report, do not assume that it was performed.

Harper’s Corner Road travels through an existing landslide failure. Shannon & Wilson’s scope of services did not include an assessment of landslide movement or global stability of the roadway.

2 PROJECT AND SITE DESCRIPTION

Harpers Corner Road (Route 011) is located within Dinosaur National Monument, which is managed by the U.S. National Parks Service (NPS) in Moffat County, Colorado (Figure 1).

The Project includes pavement improvements from the intersection of Harpers Corner Road and U.S. Highway 40 (Mile Post [MP] 0.0) to MP 14.1 of Harpers Corner Road (Figure 2).

Harpers Corner Road is a two-lane roadway that is paved with a chip seal overlying asphalt concrete pavement (ACP). The roadway winds through variable terrain in a generally north/south direction, providing visitors access to the mountains and river canyons of the Monument.

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For design purposes, we have split the Project into 3 segments by mile marker based on subgrade conditions.

Segment 1 (MP 0.0 to MP 5.2)

Segment 2 (MP 5.2 to MP 10.0)

Segment 3 (MP 10.0 to MP 14.6)

In addition, an active landslide is located between MP 5.7 and 5.8 (approximately 480 feet wide). The roadway travels in an approximate east-west direction through the landslide.

The scarp of the landslide is located approximately 150 feet south of the roadway and the toe of the landslide approximately 250 feet north of the roadway.

Based on discussions with DJ&A and Central Federal Lands Highway Division (CFLHD), the proposed improvements will consist of rehabilitation and reconstruction of the existing pavement section.

3 SUBSURFACE INVESTIGATION AND LABORATORY

TESTING

3.1 Field Investigation

Shannon & Wilson conducted a field exploration program on November 8 and 10, 2021, to explore subsurface conditions along the alignment. The subsurface exploration program consisted of drilling and sampling 31 borings designated as borings SW-01 through SW-31 at the locations shown on Figure 2. The borings were advanced to a depth ranging from approximately 4 to 15.5 feet below the existing roadway grade.

Appendix A presents a discussion of the drilling and sampling procedures used to complete the borings. Appendix A also presents the individual exploration logs and an explanation of the symbols and terminology used. Photographs of the drilling operations are provided in Appendix C.

3.2 Geotechnical Laboratory Testing

We completed geotechnical laboratory tests on selected samples retrieved from the borings to estimate index and engineering properties. The index tests included natural water content, grain size analysis, and Atterberg limits. The engineering property tests included swell/collapse and R-Value. The laboratory test results and a discussion of the testing

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107616-002 March 2022 procedures are included in Appendix B. The natural water content, fines content, and Atterberg limits are also shown on the individual boring logs included in Appendix A.

4 SUBSURFACE CONDITIONS

4.1 Regional Geology

Based on our review of 3 geologic maps of the area: Plug Hat Rock Quadrangle, Hells Canyon quadrangle, and Mellen Hill quadrangle, Rio Blanco and Moffat Counties, Colorado (Hansen and Rowley, 1980, Rowley and Hansen, 1979, and Cullins, 1969), the surficial deposits consist of dune sand, alluvium, and landslide deposits overlying bedrock. The bedrock in the area varies along the alignment and is mapped as conglomerate, sandstone, claystone, and shale. Steeply dipping bedrock is present at the beginning of the road, near borings SW-01 and SW-02, and gradually flattens as the roadway travels north into the Monument (Cullins, 1969).

4.2 Existing Pavement Thicknesses

The ACP and overlying chip seal pavement section across the project alignment ranged from 3/4 to 3 inches thick. Below the ACP, crushed aggregate base (CAB) was encountered in all borings except boring SW-21. The existing ACP and CAB (where present) thicknesses at each boring location are provided in Table A-1 in Appendix A and summarized below:

Segment 1 (MP 0.0 to MP 5.2): ACP ranging from 2-1/4 to 2-3/4 inches, CAB ranging from 2 to 5 inches.

Segment 2 (MP 5.2 to MP 10.0): ACP ranging from 2 to 3 inches, CAB ranging from 3 to 9 inches of CAB.

Segment 3 (MP 10.0 to MP 14.6): ACP ranging from ¾ to 3 inches, CAB ranging from 2 to 10 inches (CAB not encountered in SW-21).

Although the existing CAB thickness ranged from 2 to 10 inches across the Project, the CAB was observed to be 2 to 4 inches thick in 27 of the 31 borings completed. Photographs of the ACP cores is provided in Appendix C.

4.3 Pavement Subgrade

Subsurface conditions below the existing pavements varied along the project alignment. We divided the alignment into three sections designated Segment 1 through 3 based on similar geologic conditions. Individual boring logs of our explorations are presented in Appendix A. Generalized subsurface conditions consisted of:

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Segment 1 (MP 0.0 to MP 5.2): clayey sand, silty sand, sandy, silty clay [AASHTO soil classification A-2-4, A-2-6, and A-4 soils], and sandstone.

Segment 2 (MP 5.2 to MP 10.0): silty sand, clayey sand, clay with varying plasticity and percentages of sand and gravel [AASHTO soil classification A-2-6, A-6, and A-7-6 soils], and sandstone bedrock.

Segment 3 (MP 10.0 to MP 14.6): clayey sand, silty sand, clay with varying percentages of sand and gravel [AASHTO soil classification A-1-b, A-2-4, A-2-6, A-6, and A-7-6 soils], and sandstone and conglomerate bedrock.

Our observations are specific to the locations, depths, and dates noted on the exploration logs in Appendix A and may not be applicable to all areas of the site. There is no amount of explorations or laboratory testing that can precisely predict the characteristics, quality, or distribution of subsurface conditions at every location throughout the site. Variations in the subsurface conditions may occur between and below the borings. Also, the passage of time or intervening causes (natural and humanmade) may result in changes to the conditions of the site and subsurface conditions.

4.4 Groundwater

Groundwater was not encountered in any of our borings during drilling. Fluctuations of groundwater levels at the site are possible and will depend on many factors, including seasonal variations, local precipitation, and snow. Nevertheless, groundwater is not anticipated to affect the design or construction of the Project.

5 PAVEMENT ASSESSMENT

To evaluate the condition of the existing roadway pavement for potential rehabilitation options, we completed a visual pavement survey to assess the overall pavement condition and to identify areas of distress and typical crack patterns. The U.S. Fish and Wildlife Services (FWS) has developed a rating system to quantify levels of distress and to describe roadway conditions of asphalt pavements. Their 5 levels of pavement condition for asphalt are summarized below:

Asphalt Concrete Pavement

Excellent: Recently constructed or overlaid road where construction or overlay was performed correctly. No maintenance required.

Good: Low extent longitudinal and transverse cracks. All cracks are ¼ inch or less with little or no crack erosion. Patches are in good condition and applied correctly. Routine maintenance recommended.

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Fair: Roads are in good structural condition with little or no fatigue cracking.

Longitudinal, transverse, and edge cracking is at medium extent and severity. Block cracking is extensive. Any patches are in good condition. Preventative maintenance recommended.

Poor: Road beginning to show signs of structural distress. Fatigue cracking is medium to high extent and medium severity. Cracking is severe. Surface may have severe block cracking and show. Patches are in fair to poor condition. There is moderate distortion or rutting and occasional potholes. Rehabilitation recommended.

Failed: Road is severely deteriorated. Signs of structural failure appear along with severe and extensive fatigue cracking, distortion, potholes, or extensive patches in poor condition. Reconstruction recommended.

Using the FWS visual rating system, we conducted our assessment survey on October 20, 2021. We understand that the existing chip seal was placed in 2011. General pavement conditions by segment are summarized below:

Segment 1 (MP 0.0 to MP 5.2): Fair to good condition. Low extent and severity transverse and longitudinal cracking.

Segment 2 (MP 5.2 to MP 10.0): Poor to fair condition. Medium extent and severity transverse cracking. Rough riding conditions, swell related distress, patched and unpatched potholes, and areas of shoulder failure.

Segment 3 (MP 10.0 to MP 14.6): Fair to good condition. Low extent and severity transverse and longitudinal cracking.

6 PAVEMENT DESIGN RECOMMENDATIONS

Performance of a pavement system depends on the pavement material and thicknesses, subgrade strength, traffic loads and repetitions, design life, and subgrade drainage characteristics. The following sections discuss each of these aspects as they relate to the Project.

6.1 Design Methodology

Our pavement design and results are based on the design procedures presented in the 1993 AASHTO Guide for the Design of Pavement Structures (AASHTO) with guidance from the U.S. Department of Transportation and Federal Highway Administration (FHWA) Federal Lands Highway Project Development and Design Manual (PDDM), dated March 2008; and the Colorado Department of Transportation (CDOT) 2021 M-E Pavement Manual.

Pavement design inputs and calculations are presented in Appendix D.

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6.2 Traffic Loading

Traffic data was provided by NPS for the permanent counter located at Monument Headquarters near the intersection of Harpers Corner Road and U.S. Highway 40 at MP 0.0.

The traffic data included average monthly traffic from January 2016 to September 2021. The calendar year 2021 represented the highest total vehicles per year included in the study and was used in our analysis. The 2021 average daily traffic (ADT) used for design was 61 vehicles per day. A 2.0% compounded growth rate was assumed for the roadway.

The study did not include a distribution of the vehicular traffic. Based on discussions with DJ&A, information provided by NPS, and CFLHD, a traffic distribution consisting of 60% FHWA Class 2 passenger cars, 30% Class 3 pickups/vans, 1% Class 4 busses, 5% Class 5 single-unit trucks, 1% Class 6 single-unit trucks, and 3% Class 9 single-trailer trucks was assumed.

Our analysis indicated an 18-kip equivalent single axle loading (ESAL) of 39,000 given the ADT and traffic distribution mentioned previously. The PDDM indicates a minimum analysis traffic loading of 50,000 ESAL for roadways, which was used for design.

6.3 Design Subgrade R-value

Exhibit 6-1 summarizes the subsurface soils encountered and relevant laboratory test results related to our pavement design.

Exhibit 6-1: Summary of R-value Test Results

Site Location Boring

Fines Content2

(%) LL PI USCS

AASHTO Soil Classification1

R-value Test

Result Design R-Value

Harpers Corner Road

Segment 1 SW-05 28 NV NP SM A-2-4 (0) 60 50

Segment 2

SW-12 79 63 45 CH A-7-6 (36) 3

4 SW-16 75 49 31 CL A-7-6 (22) 3

SW-31 60 32 17 CL A-6 (7) 8

Segment 3

SW-24 32 28 13 SC A-2-6 (1) 14

SW-29 25 NV NP SM A-1-b (0) 63

NOTE:

AASHTO soil classification and group index included in parenthesis Fines defined as particles passing the No. 200 sieve

LL = Liquid Limit; NP = Non-Plastic; NV = No Value; PI = Plasticity Index; USCS = Unified Soil Classification System

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To estimate a design resilient modulus, we used a CDOT correlation between R-value and resilient modulus (2021). The correlation used is provided on the individual flexible pavement worksheet provided in Appendix D.

6.4 Full Depth Reclamation

We understand that a pulverized full depth reclamation (FDR) section is being considered for rehabilitation of the existing roadway pavement. The process involves pulverizing and mixing the existing asphalt with the underlying layers to create a uniformly blended, homogeneous material that will be incorporated into the proposed pavement section as a base course. The benefit of the FDR process is that it allows the existing material to be recycled in place and eliminates the expense to export the material offsite. The requirements in the PDDM indicate a minimum R-value of 70 for the pulverized FDR. In our opinion, a blended material of pulverized asphalt and existing base course will likely exceed this requirement. For our analysis, we assumed a resilient modulus of 27,000 psi for the pulverized FDR base course.

If desired, for Segment 2, we provided an alternative to incorporate additional import CAB to the FDR section thus reducing the ACP thickness. We recommend placing the appropriate volume of CAB associated with the desired FDR thickness in a windrow in front of the reclaimer prior to commencing the FDR process.

In addition to traditional FDR, we provided a Bituminous FDR design alternative in Section

6.5. Bituminous FDR involves the process of reclaiming the existing pavement section and mixing with emulsified or foamed asphalt per FP-14 Section 306.

For shoulder widening, the PDDM indicates that pulverized FDR can be used. The FDR process can accommodate approximately up to 2 feet of roadway widening with the pulverization process. Areas where the roadway is anticipated to be widened greater than 2 feet will require import CAB or stockpiling and placing excess pulverized base course from other areas of the Project. Import material should be mixed with the reclaimed FDR material and processed across the entire roadway section to provide the minimum thickness to meet the final grade below the ACP.

6.5 Recommended Pavement Sections

Using the AASHTO procedures and the parameters outlined in Appendix D, we recommend the following pavement section alternatives in Exhibit 6-2 below.

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Exhibit 6-2: Recommended Pavement Sections

Site Location Paving Alternative Recommended Pavement Section

Harpers Corner Road

Segment 1

Alt. 1 3.0 in. ACP over 5 in. FDR 1

Alt. 2 3.0 in. ACP over 4 in. Bituminous FDR 1

Alt. 3 3.0 in. ACP over 4 in. CAB 1

Segment 2

Alt. 1 4.0 in. ACP over 6 in. FDR (include 1 in of imported CAB)

Alt. 2 4.5 in. ACP over 5 in. FDR

Alt. 3 3.0 in. ACP over 5 in. Bituminous FDR 1

Alt. 4 4.0 in. ACP over 5 in. CAB

Segment 3

Alt. 1 4.0 in. ACP over 5 in. FDR

Alt. 2 3.0 in. ACP over 4 in. Bituminous FDR 1

Alt. 3 4.0 in. ACP over 4 in. CAB

NOTES:

We understand that the project team may utilize a minimum 4 inch ACP section for constructability reasons.

ACP = Asphalt Concrete Pavement; CAB = Crushed Aggregate Base; FDR = Full Depth Reclamation; in. = inch

7 ADDITIONAL CONSIDERATIONS

7.1 Subgrade Failure

We understand that the project team has identified areas of previous subgrade failure or unsuitable soil that will be subexcavated. In these areas, we recommend completing FDR and then removing the blended FDR to expose the subgrade. We then recommend subexcavating the exposed subgrade to a depth of 2 feet and placing a separation and stabilization geotextile at the base of the excavation prior to placement of import granular fill. If granular fill is used, the base of the subexcavation must be daylighted, or subgrade drains installed. If installing subdrains or daylighting the subexcavation is not feasible or is cost prohibitive, low permeable fill can be used to backfill the subexcavation (Section 8.1.3).

If desired, Stabilization Geogrid (FP-14 714.03) can be included within the subexcavation backfill to increase “bridging” over potential soft areas in the subgrade.

If granular fill is used and has a minimum R-Value of 50, the pavement sections presented for Segment 1 can be used regardless of which segment they are constructed in.

7.2 Swelling Soils

High plasticity soils in Colorado can be susceptible to volume change by swelling/shrinking.

This geologic phenomenon has the potential to cause substantial damage to lightly loaded

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107616-002 March 2022 structures, such as pavements, when exposed to water. To evaluate the swell potential for overburden surficial soils along the project alignment, we performed Atterberg Limits, moisture content, and one-dimensional swell tests on Modified California samples collected during the field exploration program. Swell testing completed from Segments 2 and 3 (samples from borings SW-12, SW-13, SW-18, and SW-26, all at a depth of 2.0 feet) indicated between 0.36 and 2.78% swell. In addition to the swell testing, we compared the in-situ moisture content of the subgrade to the plastic limit. The in-situ moisture contents in many cases throughout the Project are less than the plastic limit, indicative of soils in a potential swell susceptible state. Subgrades in Segment 1 were predominantly granular and are not considered swell susceptible.

Based on the above swell test results, the subgrade throughout Segments 2 and 3 is considered at medium risk of damage due to swell, as defined by CDOT in the 2021 Pavement Design Manual (2021) (samples exhibiting between 1 and 5% swell when tested at 200 pounds per square foot (psf) surcharge load when inundated with water).

To mitigate against potential constructability issues (pumping subgrade and difficulty achieving compaction of subgrade), as well as reducing long-term swell potential, guidance from Section 11.3.2.1.3 of the PDDM indicates:

2 feet of subexcavation (overexcavation and removal of excavated material from the site) for subgrades with a PI ranging from 15 to 25, 2 to 4 feet of subexcavation for subgrades with a PI ranging from 25 to 35 or a LL ranging from 50 to 60, and

4 to 6 feet of subexcavation for subgrades with a PI greater than 35 or a LL greater than 60.

Based on the laboratory testing completed for the Project, the required subexcavation depth would range from 2 to 6 feet in Segments 2 and 3. In lieu of subexcavation, other methods of expansive subgrade treatment can also be completed, such as lime or cement stabilization.

The PDDM notes that the subexcavation requirements should account for the traffic volume and project significance when selecting a subexcavation depth. Based on our experience on past similar CFLHD projects, we understand it is typically cost prohibitive to provide swell mitigation. If this is not the case, we recommend further coordination with the project team to select and implement swell mitigation measures.

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7.3 Landslide Area

Shannon & Wilson was not retained to analyze the landslide area located between MP 5.7 and 5.8. For roadway reconstruction and repair within the landslide limits, we recommend a maximum subexcavation depth of 2 feet and placement of low permeable fill (Section 8.1.3). If the project team elects to backfill the subexcavation within the landslide extents with clean granular soils, subgrade drains must be installed to avoid creating a bathtub effect that allows infiltration of surface water into the slide mass. We do not recommend allowing drains or subdrains to outlet within the landslide extents. Surficial runoff within the landslide should be directed away from the existing landslide.

We did not evaluate the impacts of construction-phase excavation for the subexcavation, which could potentially decrease stability of the landslide due to unloading. Significant cuts and fills should be avoided within the landslide limits. In addition, cuts into the existing failed slope should be limited or avoided to the extent possible. The project team may consider limiting the length of subexcavation that may be open at a given time to minimize changes to the landslide loading that could decrease stability.

7.4 Frost Damage

Frost susceptible soils can lead to pavement performance issues due to heaving or deformation from ice lenses forming in the underlying soil and pavement fatigue damage due to thaw-weakened subgrade of the springtime freeze-thaw cycle (USDOT, FHWA, 2008). Frost susceptible soils typically include fine-grained soils such as silts and clays. In accordance with the PDDM, typical treatment for frost susceptible soils consists of assuring there is an adequate pavement layer structure to account for the loss of bearing capacity during the spring thaw and removing or replacing highly frost susceptible soil for a portion of the expected frost depth. Based on our experience on past CFLHD projects, we understand it is typically cost prohibitive to provide protection against frost heave on similar projects. If this is not the case, we recommend partial removal and replacement with non-frost susceptible materials (up to about 70% of the frost depth of 36 inches), and we should be contacted to provided alternative pavement sections and drainage recommendations accounting for this condition.

8 CONSTRUCTION AND MATERIAL SPECIFICATIONS

The applicability of the recommendations in Section 7 is contingent on good construction practice. Poor construction techniques may alter conditions from those upon which our recommendations are based, and therefore result in poor performance. Our analyses

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107616-002 March 2022 assumed that the Project is constructed according to FP-14 U.S. Customary Units (USDOT and FHWA, 2014) construction standards. The following sections provide additional construction considerations for the Project.

8.1 Earthwork

8.1.1 General

Earthwork, including placement of fill and subgrade preparation, should conform to the requirements provided in the FP-14 U.S. Customary Units, (USDOT and FHWA, 2014) and the recommendations provided in the following sections.

8.1.2 Subgrade Preparation and Fill Placement

In areas where FDR is not performed, or performed but removed to address subgrade failure, the subgrade should be prepared in accordance with FP-14 Section 204.11. All subgrade material and fill should be compacted to a dense/firm and unyielding condition.

Additionally, subgrades should be protected from drying or wetting in excess of what is required to achieve the specified compaction requirements.

Granular fill material for the Project should consist of Structural Backfill, (FP-14 704.04), Select Granular Backfill (FP-14 704.08), or Unclassified Borrow (FP-14 704.06) with the additional requirement of a maximum particle size of 3 inches. In areas where daylighting the subgrade or subdrains are not used, we recommend backfilling with Low Permeable Fill (Section 8.1.3).

8.1.3 Low Permeable Fill

Due to the presence of expansive soils at the site, we do not recommend replacing the subgrade over-excavation with clean granular soils if the material will not be daylighted or subdrains are utilized, as there will be no natural drainage, and this can form a bathtub effect that can exacerbate swell. Instead, we recommend using low permeable fill in subexcavation areas, conforming to the following requirements:

Fines content between 36 and 50% (AASHTO Classification A-4 and A-6).

PI less than 20.

Be low swell susceptible (swell of less than 1% when wetted under a surcharge load of 200 pounds per square foot when tested with ASTM D4546).

Minimum R-value of 4.

Free of organics, contaminants, debris, and rock fragments larger than 3 inches.

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8.1.4 Proof-Rolling

As discussed above, the subgrade should be prepared in accordance with FP-14 Section 204.11, which includes the use of compression-type rollers. While it is important to place clayey material above the optimum moisture content to control swell, material placed wet of optimum is prone to pumping and yielding from construction activities. This material can be difficult to pass a proof-roll. The Contractor will need to carefully control the movement of equipment around the site and minimize the passage of equipment over exposed subgrades. Even with these precautions, compaction of the material will be difficult and extra working time should be anticipated. Placement and compaction testing should be monitored on a full-time basis to assist in this process.

8.2 Paving Materials

The following Exhibit 8-1 summarizes our recommendations for pavement material selection using the FP-14 specifications.

Exhibit 8-1: Recommended Materials for Pavements

Material FP-14 Specification Additional Requirements/Comments

CAB Section 301 Use Gradation C, D, or E

FDR Section 304 -

Bituminous FDR Section 306 -

CIR Section 310 -

ACP Section 401 (FP-14)

Aggregate Gradation: (1/2-inch or 3/4-inch NMAS) PG Binder: PG 64-34 for all lifts, Gyratory Number (N): 75

Subgrade Stabilization and Separator Geotextile

Section 714.01 Class 1 Separation and Stabilization Geotextile Maximum AOS 0.3 mm

NOTE:

AOS = Apparent Opening Size; ACP = Asphalt Concrete Pavement; CAB = Crushed Aggregate Base; CDOT = Colorado Department of Transportation; FDR = Full Depth Reclamation; mm = Millimeters; NMAS = Nominal Maximum Aggregate Size; PG = Performance Grade

The binder selection procedure is based on the anticipated pavement temperatures, traffic patterns, and local availability. The PDDM specifies the use of software developed by the FHWA Long Term Pavement Performance (LTPP) Bind Version 3.1Beta to determine an appropriate binder for a 95% reliability performance for both high and low temperature ranges. The LTPP Bind software indicates a performance grade (PG) of PG 64-28 for surface lifts and PG 64-22 for lower lifts for the site and anticipated traffic loading. Appendix D provides the output from the LTPP Bind software. Based on discussions with the project team we understand that PG 64-34 will be used for the Project to provide higher performance at the lower temperature range.

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In addition, we recommend using a ½-inch nominal maximum aggregate size (NMAS) mix for the surface layer of HMA and ¾-inch NMAS for underlying lifts. CDOT recommends lift thickness for ½ inch NMAS between 1-1/2 and 3 inches and 2-1/4 and 3-1/2 inches for ¾ inch NMAS. In addition, a tack coat should be placed between subsequent lifts.

9 CLOSURES

This report has been prepared for the exclusive use of DJ&A and the Central Federal Lands Highway Division for the purpose of providing pavement recommendations for the Harpers Corner Road improvements Project. This pavement design report should not be used without our approval if any of the following occurs:

Assumptions stated in this report have changed.

Project details change or new information becomes available such that our analyses and recommendations may be affected.

A substantial period of time has passed since the date of this report.

If any of these occur, we should be retained to review the applicability of our analyses and recommendations.

Within the limitations of scope, schedule and budget, the analyses, conclusions and recommendations presented in this report were prepared in accordance with generally accepted professional geotechnical and geological principles and practice in this area at the time this report was prepared. We make no other warranty, either express or implied.

Shannon & Wilson has prepared “Important Information about Your Geotechnical Report,” to assist you and others in understanding the use and limitations of our reports.

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10 REFERENCES

American Association of State Highway and Transportation Officials (AASHTO), 1993, AASHTO guide for design of pavement structures: Washington, D.C., AASHTO, 2 v.

Colorado Department of Transportation (CDOT), 2021, 2021 M-E Pavement Design Manual;

available: https://www.codot.gov/business/designsupport/materials-and-geotechnical/manuals/2021-m-e-pave-design-manual

Cullins, H.L., 1969, Geologic map of the Mellen Hill quadrangle, Rio Blanco and Moffat Counties, Colorado, U.S. Geological Survey, Geologic Quadrangle Map GQ- 835, 1:24,000.

Federal Highway Administration (FHWA), 2021, LTPP InfoPave: Tools: LTPPBind Online, available at: https://infopave.fhwa.dot.gov/Tools/LTPPBindOnline.

Hansen, W.R. and Rowley, P.D., 1980, Geologic map of the Hells Canyon quadrangle, Moffat County, Colorado, U.S. Geological Survey, Geologic Quadrangle Map GQ- 1536, 1:24,000.

Rowley, P.D., and Hansen, W.R., 1979, Geologic map of the Plug Hat Rock quadrangle, Moffat County, Colorado, U.S. Geological Survey, Geologic Quadrangle Map GQ- 1514, 1:24,000.

U.S. Department of Transportation (USDOT), FHWA, 2014, Federal standard specifications for construction of roads and bridges on Federal Highway projects, FP-14 English Units: U.S. Department of Transportation and Federal Highway Administration, available: https://highways.dot.gov/federal-lands/specs

USDOT, FHWA, 2008, Federal Lands Highway project development and design manual (PDDM): U.S. Department of Transportation and Federal Highway Administration; available: http://flh.fhwa.dot.gov/resources/manuals/pddm/

U.S. Fish and Wildlife Service (FWS). Road Inventory Program Rating System.

https://www.codot.gov/business/designsupport/materials-and-geotechnical/manuals/2021-m-e-pave-design-manual https://www.codot.gov/business/designsupport/materials-and-geotechnical/manuals/2021-m-e-pave-design-manual http://flh.fhwa.dot.gov/resources/manuals/pddm/

White Riv er

Y e ll o w C re e k

Browns Park Nat'l Wildlife

Refuge Ashley National

Forest

Dinosaur National Monument

Vernal

B itte r C re e k

Uintah and Ouray

Reservation

Denver

Colorado Springs

Pueblo

Fort Collins

Grand Junction

0 10 20

Miles

CO FTNP DINO 11(1)

Harpers Corner Road

Moffat County, Colorado

March 2022

VICINITY MAP

FIG. 1

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SHANNON & WILSON, INC.

Geotechnical and Environmental Consultants

Project Location

Esri, HERE, Garmin, SafeGraph, FAO, METI/NASA, USGS, Bureau of Land Management, EPA, NPS, Esri, USGS, Esri, Garmin, FAO, NOAA, EPA

Project Location

Rangely

0 1,000 2,000

Approximate Scale In Feet

CO FTNP DINO 11(1)

Harpers Corner Road

Moffat County, Colorado

SITE AND EXPLORATION PLAN

FIG. 2

March 2022 107616-002

SHANNON & WILSON, INC.

Geotechnical and Environmental Consultants

M atch

Lin e S h eet 2

H ig hw ay

Harpers Corner Rd

MP 0

MP 1

MP 2

SW-01

SW-02

SW-03

SW-04

SW-05

SW-06

Monument Headquarters

Bull Canyon

WSA

Willow Creek

WSA

Skull Creek

WSA

Bull Canyon

WSA N

LEGEND

!> Approximate Boring Location and DesignationSW-01

Project Mile PostsMP 1

Sheet 1 of 5

Esri, HERE, Garmin, SafeGraph, FAO, METI/NASA, USGS, Bureau of Land Management, EPA, NPS, © 2021 Microsoft Corporation © 2021 Maxar ©CNES (2021) Distribution Airbus DS

CO FTNP DINO 11(1)

Harpers Corner Road

Moffat County, Colorado

SITE AND EXPLORATION PLAN

FIG. 2

March 2022 107616-002

SHANNON & WILSON, INC.

Geotechnical and Environmental Consultants

M atch

Lin e S h eet 3

Match Line Sheet 1

Harpers Corner Rd

MP 3

MP 4

MP 5

MP 6

SW-06

SW-07

SW-08

SW-09

SW-10 SW-11

SW-12 SW-30

Bull Canyon

WSA

Willow Creek

WSA

Skull Creek

WSA

Bull Canyon

WSA N

LEGEND

!> Approximate Boring Location and DesignationSW-01

Project Mile PostsMP 1

Sheet 2 of 5

Esri, HERE, Garmin, SafeGraph, FAO, METI/NASA, USGS, Bureau of Land Management, EPA, NPS, © 2021 Microsoft Corporation © 2021 Maxar ©CNES (2021) Distribution Airbus DS

CO FTNP DINO 11(1)

Harpers Corner Road

Moffat County, Colorado

SITE AND EXPLORATION PLAN

FIG. 2

March 2022 107616-002

SHANNON & WILSON, INC.

Geotechnical and Environmental Consultants

!> M atch

Lin e S h eet 4

Match Line Sheet 2

Harp ers

Co rne r R d

MP 6

MP 7

MP 8

MP 9

SW-12

SW-13

SW-14

SW-15

SW-16

SW-17

SW-18

SW-19

SW-30

Bull Canyon

WSA

Willow Creek

WSA

Skull Creek

WSA

Bull Canyon

WSA N

LEGEND

!> Approximate Boring Location and DesignationSW-01

Project Mile PostsMP 1

Sheet 3 of 5

Esri, HERE, Garmin, SafeGraph, FAO, METI/NASA, USGS, Bureau of Land Management, EPA, NPS, © 2021 Microsoft Corporation © 2021 Maxar ©CNES (2021) Distribution Airbus DS

CO FTNP DINO 11(1)

Harpers Corner Road

Moffat County, Colorado

SITE AND EXPLORATION PLAN

FIG. 2

March 2022 107616-002

SHANNON & WILSON, INC.

Geotechnical and Environmental Consultants

M atch

Lin e S h eet 5

Matc h Li ne Sheet 3

Harpers Corner Rd

MP 9

MP 10

MP 11

SW-19

SW-20

SW-21

SW-22

SW-23

SW-24

SW-31

Bull Canyon

WSA

Willow Creek

WSA

Skull Creek

WSA

Bull Canyon

WSA N

LEGEND

!> Approximate Boring Location and DesignationSW-01

Project Mile PostsMP 1

Sheet 4 of 5

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CO FTNP DINO 11(1)

Harpers Corner Road

Moffat County, Colorado

SITE AND EXPLORATION PLAN

FIG. 2

March 2022 107616-002

SHANNON & WILSON, INC.

Geotechnical and Environmental Consultants

M atch Line Sheet 4

Harpers Corner Rd

MP 12

MP 13

MP 14

SW-25

SW-26

SW-27

SW-28

SW-29

Bull Canyon

WSA

Willow Creek

WSA

Skull Creek

WSA

Bull Canyon

WSA N

LEGEND

!> Approximate Boring Location and DesignationSW-01

Project Mile PostsMP 1

Sheet 5 of 5

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3/23/2022-107616-002_AA.docx A-i

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Appendix A: Subsurface Explorations

Appendix A

Subsurface Explorations

CONTENTS

A.1 Introduction ........................................................................................................................... A-1

A.2 Explorations ........................................................................................................................... A-1

A.2.1 Soil and Rock Classification System ...................................................................... A-1

A.2.2 Standard Penetration Test (SPT) ............................................................................ A-2

A.2.3 Modified California (MC) Test and Sampling ..................................................... A-2

A.2.4 Bulk Sampling .......................................................................................................... A-3

Tables Table A-1: Summary of Existing Pavement Section Thickness

Figures Figure A-1: Soil Description and Log Key Figure A-2: Rock Classification and Log Key Figure A-3 through A-33: Log of Borings SW-01 through SW-31

A-1

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A.1 INTRODUCTION

Shannon & Wilson’s field exploration program was conducted on November 8 to 10, 2021, and consisted of drilling 31 borings, designated SW-01 through SW-31 at the locations shown on Figure 2. Photographs of drilling locations and asphalt cores are provided in Appendix C. The methods used to conduct the field exploration program are described below.

A.2 EXPLORATIONS

The borings were coordinated (including subcontractor coordination, traffic control, and utility locates) and observed by a Shannon & Wilson field representative. Individual boring logs are presented in Figures A-3 through A-33. These exploration logs represent our interpretation of the contents of the field logs and select results of laboratory testing. The borings were drilled by Vine Laboratories, Inc. of Commerce City, Colorado (under subcontract to Shannon & Wilson) using a truck mounted CME 55 drill rig. The borings were advanced to depths ranging from approximately 4.0 to 15.5 feet utilizing 4-inch solid-stem-auger drilling methods. Groundwater was not encountered during drilling in any of the borings. On completion of drilling, the borings were backfilled with cuttings and bentonite chips and patched with cold patch asphalt.

A.2.1 Soil and Rock Classification System

During exploration, our representative collected samples and prepared field logs of the explorations. Soil classification for this project was based on ASTM Designation: D2487, Standard Practice for Classification of Soils for Engineering Purposes (Unified Soil Classification System), and ASTM Designation: D2488, Standard Practice for Description and Identification of Soils (Visual-Manual Procedure). Soils were also classified using the AASHTO Soil Classification System based on AASHTO Standard M 145. The Unified Soil Classification System is summarized in Figure A-1. The Shannon & Wilson representative classified rock samples in general accordance with the International Society of Rock Mechanics (ISRM) classification method. According to this system, rocks are classified based on the stratigraphic structure, rock strength, degree of weathering, and other properties. The rock classification system is summarized in Figure A-2.

Consistent with other locations in Colorado, in some locations the bedrock encountered in the borings was found to be hard when considered as a lithified soil material. However, when compared with other types of bedrock using the ISRM classification of rock strength, A-2

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the material resembles a very low strength rock. Therefore, for completeness, the boring logs included in Appendix A contain dual descriptions of the bedrock using the Unified Soil Classification System and the ISRM classification system where appropriate.

A.2.2 Standard Penetration Test (SPT)

Disturbed samples were obtained in the borings in general accordance with the Standard Penetration Test (SPT) (ASTM Designation: D1586). The SPT consists of driving a 2-inch outside diameter, 1.375-inch inside diameter split-spoon sampler a distance of 18 inches with a 140-pound hammer free-falling a distance of 30 inches. An automatic hammer system was used to advance the samplers. During sampling, the Shannon & Wilson field representative recorded the number of blows for each 6-inch increment of penetration and summed the blow counts for the last two 6-inch increments. This sum is recorded as the penetration resistance number, or N-value. If high penetration resistance prevented driving the total length of the sampler, the Shannon & Wilson field representative recorded the partial penetration depth and blow count. The N-values provide a means for evaluating the relative density or compactness of cohesionless (granular) soils and consistency or stiffness of cohesive (fine-grained) soils (see Figure A-1). The raw N-values are shown on the individual boring logs. Representative portions of the split-spoon sample obtained in conjunction with the SPT were placed in a screw-top plastic jar and transported to our laboratory.

A.2.3 Modified California (MC) Test and Sampling

Samples were also obtained using a modified California (MC) barrel sampler. The MC test procedure is similar to the SPT, except a larger diameter barrel sampler (2½-inch O.D., lined with 2-inch-diameter brass tubing) is used and only driven 12 inches. During sampling, the Shannon & Wilson field representative recorded the number of blows for each 6-inch increment of penetration. As a result of the larger diameter, the MC sampler yields slightly higher raw blow count numbers when compared to SPT N-values for similar soils. Because the difference in blow counts does not significantly impact our evaluation, we used the field MC blow counts over the 12-inch increment to define the relative density and consistency/stiffness of the subsurface materials following SPT terminology. Representative samples were sealed in the brass liner tubes with plastic caps and transported to our laboratory.

A-3

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A.2.4 Bulk Sampling

Bulk soil samples were obtained by collecting the drill cuttings from the upper several feet of select borings. Approximately 20 to 30 pounds of cuttings were placed in a plastic bag and transported to our laboratory for further analysis and testing.

Pavement Design Report

Roadway Design Segment Boring Asphalt

Thickness Base Course

Thickness

(in) (in)

SW-01 2 1/4 5

SW-02 2 1/2 2

SW-03 2 1/2 3

SW-04 2 3/4 2

SW-05 2 1/2 3

SW-06 2 3/4 2

SW-07 2 3/4 3

SW-08 2 1/4 3

SW-09 2 3/4 2

SW-10 2 3/4 3

SW-11 2 1/4 4

SW-12 3 3

SW-13 2 4

SW-14 2 1/2 3

SW-15 3 9

SW-16 2 1/2 3

SW-17 3 4

SW-18 2 4

SW-19 2 1/2 4

SW-20 2 1/2 3

SW-21 3 NE

SW-22 2 1/2 3

SW-23 3 2

SW-24 2 3/4 3

SW-25 2 1/2 3

SW-26 2 3/4 3

SW-27 2 1/2 3

SW-28 2 1/4 4

SW-29 3 4

SW-30 1 1/2 3

SW-31 3/4 10

NOTES:

NE = not encountered, in = inches

Table A-1 - Summary of Existing Pavement Section Thickness

Harpers Corner Road

Segment 1

Segment 2

Segment 3

107616-002 Page 1 of 1 107616-002_TA1 - HarpersCorner.xlsx - 1/20/2022

March 2022 107616-002

Harpers Corner Road

Moffat County, Colorado

1Gravel, sand, and fines estimated by mass. Other constituents, such as organics, cobbles, and boulders, estimated by volume.

2Reprinted, with permission, from ASTM D2488 - 09a Standard Practice for Description and Identification of Soils (Visual-Manual Procedure), copyright ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428.

A copy of the complete standard may be obtained from ASTM International, www.astm.org.

140 pounds with a 30-inch free fall.

Rope on 6- to 10-inch-diam. cathead 2-1/4 rope turns, > 100 rpm

NOTE: If automatic hammers are used, blow counts shown on boring logs should be adjusted to account for efficiency of hammer.

10 to 30 inches long Shoe I.D. = 1.375 inches Barrel I.D. = 1.5 inches Barrel O.D. = 2 inches

Sum blow counts for second and third 6-inch increments.

Refusal: 50 blows for 6 inches or less; 10 blows for 0 inches.

RELATIVE

CONSISTENCY

N, SPT,

BLOWS/FT.

5% to 12% fine-grained:

with Silt or with Clay 3

15% or more of a second coarse-grained constituent:

with Sand or with Gravel 5

< 5%

5 to 10%

15 to 25%

30 to 45%

50 to 100%

Surface Cement Seal

Asphalt or Cap

Slough

Inclinometer or Non-perforated Casing

Vibrating Wire Piezometer

N, SPT,

BLOWS/FT.

< 4 4 - 10

10 - 30 30 - 50

> 50

DESCRIPTION

< #200 (0.075 mm = 0.003 in.)

#200 to #40 (0.075 to 0.4 mm; 0.003 to 0.02 in.)

#40 to #10 (0.4 to 2 mm; 0.02 to 0.08 in.)

#10 to #4 (2 to 4.75 mm; 0.08 to 0.187 in.)

SIEVE NUMBER AND/OR APPROXIMATE SIZE

#4 to 3/4 in. (4.75 to 19 mm; 0.187 to 0.75 in.)

3/4 to 3 in. (19 to 76 mm)

3 to 12 in. (76 to 305 mm)

> 12 in. (305 mm)

Fine Coarse

Fine Medium Coarse

BOULDERS

COBBLES

GRAVEL

FINES

SAND

Sheet 1 of 3

CONSTITUENT2

SOIL DESCRIPTION

AND LOG KEY

SHANNON & WILSON, INC.

Geotechnical and Environmental Consultants

Absence of moisture, dusty, dry to the touch

Damp but no visible water

Visible free water, from below water table

FIG. A-1

Shannon & Wilson, Inc. (S&W), uses a soil identification system modified from the Unified Soil Classification System (USCS). Elements of the USCS and other definitions are provided on this and the following pages. Soil descriptions are based on visual-manual procedures (ASTM D2488) and laboratory testing procedures (ASTM D2487), if performed.

STANDARD PENETRATION TEST (SPT)

SPECIFICATIONS

Hammer:

Sampler:

N-Value:

Dry

Moist

Wet

MOISTURE CONTENT TERMS

Modifying (Secondary)

Precedes major constituent

Major

Minor Follows major constituent

1All percentages are by weight of total specimen passing a 3-inch sieve.

2The order of terms is: Modifying Major with Minor.

3Determined based on behavior.

4Determined based on which constituent comprises a larger percentage.

5Whichever is the lesser constituent.

COARSE-GRAINED

SOILS

(less than 50% fines)1

NOTE: Penetration resistances (N-values) shown on boring logs are as recorded in the field and have not been corrected for hammer efficiency, overburden, or other factors.

PARTICLE SIZE DEFINITIONS

RELATIVE DENSITY / CONSISTENCY

Sand or Gravel 4

30% or more coarse-grained:

Sandy or Gravelly 4

More than 12% fine-grained:

Silty or Clayey 3

15% to 30% coarse-grained:

with Sand or with Gravel 4

30% or more total coarse-grained and lesser coarse-grained constituent is 15% or more:

with Sand or with Gravel 5

Very soft Soft Medium stiff Stiff Very stiff Hard

Very loose Loose Medium dense Dense Very dense

RELATIVE

DENSITY

FINE-GRAINED SOILS

(50% or more fines)1

COHESIVE SOILS

< 2 2 - 4 4 - 8

8 - 15 15 - 30

> 30

COHESIONLESS SOILS

Silt, Lean Clay, Elastic Silt, or

Fat Clay 3

PERCENTAGES TERMS 1, 2

Trace

Few

Little

Some

Mostly

WELL AND BACKFILL SYMBOLS

Bentonite Cement Grout

Bentonite Grout

Bentonite Chips

Silica Sand

Perforated or Screened Casing

S&W INORGANIC SOIL CONSTITUENT DEFINITIONS

S O

IL

_C

LA

S

S _K

E Y

_P G

6-

2_ H

A R

P E

R S

C O

R N

E R

.G P

J S

H A

N _W

IL

.G

D T

/2 0/

Harpers Corner Road

Moffat County, Colorado

GC

SC

Inorganic

Organic

(more than 50% of coarse fraction retained on No. 4 sieve)

MAJOR DIVISIONS GROUP/GRAPHIC

SYMBOL

CH

OH

ML

CL

TYPICAL IDENTIFICATIONS

Gravel

Sand

Silty Sand; Silty Sand with Gravel

Clayey Sand; Clayey Sand with Gravel

Clayey Gravel; Clayey Gravel with Sand

Sheet 2 of 3

Gravels

Primarily organic matter, dark in color, and organic odor

SW

(more than 12% fines)

Silts and Clays

Silts and Clays

(more than 50% retained on No.

200 sieve)

(50% or more of coarse fraction passes the No. 4 sieve)

(liquid limit less than 50)

(liquid limit 50 or more)

Organic

Inorganic

FINE-GRAINED

SOILS

SM

Sands

Silty or Clayey Gravel

Silt; Silt with Sand or Gravel; Sandy or Gravelly Silt

Organic Silt or Clay; Organic Silt or Clay with Sand or Gravel; Sandy or Gravelly Organic Silt or Clay

HIGHLY-

ORGANIC

SOILS

COARSE-

GRAINED

SOILS

OL

(less than 5% fines)

GW

Geotechnical and Environmental Consultants

SHANNON & WILSON, INC.

(less than 5% fines)

PT

FIG. A-1

(more than 12% fines)

MH

SP

GP

GM

Silty or Clayey Sand

Silty Gravel; Silty Gravel with Sand

(50% or more passes the No.

200 sieve)

SOIL DESCRIPTION

AND LOG KEY

Elastic Silt; Elastic Silt with Sand or Gravel; Sandy or Gravelly Elastic Silt

Fat Clay; Fat Clay with Sand or Gravel;

Sandy or Gravelly Fat Clay

Organic Silt or Clay; Organic Silt or Clay with Sand or Gravel; Sandy or Gravelly Organic Silt or Clay

Poorly Graded Sand; Poorly Graded Sand with Gravel

Well-Graded Sand; Well-Graded Sand with Gravel

Well-Graded Gravel; Well-Graded Gravel with Sand

Poorly Graded Gravel; Poorly Graded Gravel with Sand

Lean Clay; Lean Clay with Sand or Gravel; Sandy or Gravelly Lean Clay

Peat or other highly organic soils (see

ASTM D4427)

NOTES

1. Dual symbols (symbols separated by a hyphen, i.e., SP-SM, Sand with Silt) are used for soils with between 5% and 12% fines or when the liquid limit and plasticity index values plot in the CL-ML area of the plasticity chart. Graphics shown on the logs for these soil types are a combination of the two graphic symbols (e.g., SP and SM).

2. Borderline symbols (symbols separated by a slash, i.e., CL/ML, Lean Clay to Silt; SP-SM/SM, Sand with Silt to Silty Sand) indicate that the soil properties are close to the defining boundary between two groups.

S O

IL

_C

LA

S

S _K

E Y

_P G

6-

2_ H

A R

P E

R S

C O

R N

E R

.G P

J S

H A

N _W

IL

.G

D T

/2 0/

NOTE: No. 4 size = 4.75 mm = 0.187 in.; No. 200 size = 0.075 mm = 0.003 in.

UNIFIED SOIL CLASSIFICATION SYSTEM (USCS)

(Modified From USACE Tech Memo 3-357, ASTM D2487, and ASTM D2488)

Harpers Corner Road

Moffat County, Colorado

SHANNON & WILSON, INC.

Geotechnical and Environmental Consultants

FIG. A-1

Sheet 3 of 3

SOIL DESCRIPTION

AND LOG KEY

1Reprinted, with permission, from ASTM D2488 - 09a Standard Practice for Description and Identification of Soils (Visual-Manual Procedure), copyright ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428. A copy of the complete standard may be obtained from ASTM International, www.astm.org.

2Adapted, with permission, from ASTM D2488 - 09a Standard Practice for Description and Identification of Soils (Visual-Manual Procedure), copyright ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428. A copy of the complete standard may be obtained from ASTM International, www.astm.org.

Interbedded

Laminated

Fissured

Slickensided

Blocky

Lensed

Homogeneous

ATD

Diam.

Elev.

ft.

FeO gal.

Horiz.

HSA

I.D.

in.

lbs.

MgO mm

MnO

NA

NP

O.D.

OW

pcf

PID

PMT

ppm psi

PVC

rpm

SPT

USCS

qu

VWP

Vert.

WOH

WOR

Wt.

Crumbles or breaks with handling or slight finger pressure.

Crumbles or breaks with considerable finger pressure.

Will not crumble or break with finger pressure.

PLASTICITY2

CEMENTATION TERMS1

GR…