GEOSCIENCE ENGINEERING & TESTING, INC.

GEOTECHNICAL EXPLORATION AND

PAVEMENT SUBGRADE EVALUATION

Proposed City of Conroe Street Rehabilitation and Drainage South Pine Lake Road, South of SH 105 Conroe, Texas PO Number: 26-02470

Reported to:

City of Conroe Engineering Conroe, Texas

Prepared by:

Geoscience Engineering and Testing, Inc.

Houston, Texas

PROJECT NO: 26G13427

April 2026

April 27, 2026 City of Conroe Engineering 700 Metcalf Street Conroe, TX 77301

Attention: Ms. Jennifer Gilmore Engineering Projects Coordinator

Reference: GEOTECHNICAL EXPLORATION AND PAVEMENT SUBGRADE EVALUATION

Proposed City of Conroe Street Rehabilitation and Drainage South Pine Lake Road, South of SH 105 Conroe, Texas PO Number: 26-02470

GETI NO: 26G13427

Dear Ms. Gilmore:

GEOSCIENCE ENGINEERING & TESTING, INC. (GETI) is pleased to submit this report for the above-referenced project. This study was authorized by Mr. Tara B. Gaha, PE, of the City of Conroe Engineering, through a professional agreement dated March 19, 2026, based on GETI Proposal No.

26-13178, dated March 17, 2025. This report describes the procedures employed in our investigation for the pavement improvements and drainage of South Pine Lake Road, South of SH 105, and presents the conclusions and recommendations of our studies.

We appreciate the opportunity to work with you on this phase of the project. If you have any questions concerning this report or require additional information, please contact us.

With Kindest Regards, Geoscience Engineering & Testing, Inc.

Jozyril Jalique, EIT Roham Golrokh, PE Telfryn L. John, PE Staff Engineer Vice President - Engineering Services Principal Engineer

F-4802 Copies Submitted: (1)

TABLE OF CONTENTS

EXECUTIVE SUMMARY

I. INTRODUCTION AND PROJECT INFORMATION

II. SUBSURFACE EXPLORATION

1. General / Scope of Work

2. Description of the Site

3. Site Geology and Surface Fault

4. Field Investigation

4.1 Field Strength Tests

4.2 Water Level Measurement

5. Asphalt Core Data

6. Laboratory Testing

III. GENERAL DESCRIPTION OF SUBSURFACE MATERIALS

1. General Stratigraphy

2. Swell Potential

3. Potential Vertical Rise (PVR)

4. Near Surface Moisture Retentive Soil

5. Existing Pavement Thickness

IV. EXISTING PAVEMENT EVALUATIONS AND RECOMMENDATIONS

1. Evaluation of Existing Asphalt Pavement

1.1 Asphalt Content and Bituminous Mixtures

1.2 Gradation

2. Suitability for Re-Use

V. PAVEMENT RECOMMENDATIONS

1. Flexible Pavement

1.1 Mill and Overlay Existing Asphalt Pavement

1.2 Mill Existing Asphalt Pavement, Pulver Mix with Existing Subgrade and Stabilize

1.3 Pavement Coatings

VI. DRAINAGE DITCHES AND CULVERTS

VII. GENERAL CONSTRUCTION CONSIDERATIONS

1. Site Preparation

2. Structural Fill and Subgrade Preparation

3. Surface Drainage and Erosion Control

VIII. DISCLAIMER

City of Conroe | South Pine Lake Road

GETI NO.: 26G13427

EXECUTIVE SUMMARY

Geoscience Engineering and Testing, Inc. (GETI) conducted an investigation of subsurface conditions at the site of the Conroe Street Rehabilitation and Drainage of South Pine Lake Road, South of SH 105, with an alignment approximately 4,000 linear feet, from Pleasure Court intersection toward the south, in Conroe, Texas. GETI’s investigation was authorized by Mr. Tara B. Gaha, PE, of the City of Conroe Engineering, on March 19, 2026, and thereafter Purchase Order No. 26-02470, dated March 24, 2026, and was performed in accordance with GETI Proposal No. 26-13178, dated March 17, 2026.

The purpose of the geotechnical investigation was to determine the subsurface conditions at the site with particular reference to the evaluation of existing pavement, subsurface, and ground water conditions, and recommendations for street rehabilitation (mill and overlay) covering approximately 4,000 linear feet of asphaltic concrete pavement on South Pine Lake Road, Conroe. The project scope also includes minor drainage improvements such as culvert replacements and ditch cleaning/regrading. See below for the City of Conroe preliminary site plan and suggested boring locations.

This geotechnical report was prepared based on the geotechnical exploration, pavement evaluation, and assessment of the material obtained from the above 4 asphalt/base cores and 4 soil test borings along the South Pine Lake Road, South of SH 105, in Conroe, Texas.

Based on visual observation, the existing pavement exhibited signs of fatigue cracking, longitudinal cracking, transverse cracking, and rutting, possibly related to increasing heavy-duty transit and the existing pavement age and quality, including a limited surface course along the project alignment. The cracks observed were in the center of the road and near both shoulders. Some pictures are presented in the appendices of this report associated with the existing pavement conditions.

Coring revealed 2 to 3½ -inch variable thickness asphaltic concrete, predominantly made of one or two layers over 9 to 14 inches of loose or compacted base materials. Refer to Section III of the report for more details.

According to the obtained results, however, the surface soil below asphaltic concrete pavement and base layers comprised primarily loose silty sand to the maximum depth of drilling of 6-ft., B-2 through B-4, or sandy lean clay (one location), followed by clayey sand and sandy fat clay, B-1, at the time of drilling operations.

Ground water was NOT encountered in the borings during the drilling operation to the maximum drilled depth of 6-feet.

Summary of the Findings, Conclusions and Recommendations of the Study:

➢ Asphalt content of the existing pavement was assessed between the 4 cores evaluated and ranged from 4.1 to 4.3 percent. Specific gravity ranged from SG = 2.504 to 2.531. Average specimen density ranged from approximately 90.2 to 93.7 percent. The gradation results indicate that the existing asphaltic concrete pavement aggregates mostly meet the standard TxDOT specifications and can be reused.

Asphalt surface course can be milled in preparation for an overlay. However, the City of Conroe may also wish to consider the cement stabilization or cement treatment of the milled surface course with existing base materials, which can be pulverized, mixed, and treated with cement along with the milled materials specified by TXDOT Item 275. This latter option would provide a more robust pavement section using 10 percent cement addition to a depth of 8-inches minimum.

➢ GETI performed pavement thickness analysis for the rehabilitation of a flexible pavement system.

The associated results are provided later in this report. TxDOT latest Traffic Counts AADT in 2021 for South Pine Lake Road are 1,424 AADT near SH 105, and 1,125 further south near the project end.

➢ Minor drainage improvements are also planned at a few culvert locations which cross beneath the pavement. These should be bedded in accordance with the City of Conroe Engineering Design Manual. Regardless, beneath the improved roadway, RCP pipe should be bedded in cement-stabilized sand CSS for new and improved culverts along the alignment.

➢ The new surface course should be preceded by level up layer of asphaltic concrete, with recommended thicknesses as follows:

o Level Up Course 1.0 to 1.5 inches TxDOT Item 7053 Special o Surface Course 2.5 to 3.0 inches TxDOT Item 340/341

LEFT BLANK INTENTIONALLY

I. INTRODUCTION AND PROJECT INFORMATION

Geoscience Engineering and Testing, Inc. (GETI) is pleased to submit this report of our geotechnical investigation and shallow subgrade evaluation associated with the Proposed City of Conroe Street Rehabilitation and Drainage Improvements for South Pine Lake Road, South of SH 105 with an alignment approximately 4,000 linear feet, in Conroe, Texas. GETI’s investigation was authorized by Jennifer Gilmore with City of Conroe Public Works, on March 19, 2026, and thereafter via Purchase Order No. 26-02470, dated March 24, 2026, performed in accordance with GETI Proposal No. 26-13178, dated March 17, 2026.

At the time of this study, South Pine Lake Road is a two-way two lane, undivided asphaltic concrete pavement with shallow drainage ditches either side and a few under pavement culvert crossings. Several storage businesses are situated on the north and south side of South Pine Lake Road in this alignment, including Lakeside Landing and Boat Storage and Pinelake Storages. Average Daily Traffic (AADT) counts were available from the TxDOT database for 2021. South Pine Lake Road has 1,424 AADT near SH 105, and 1,125 AADT further south near the project end. Traffic usage, pavement ESALs, and general traffic is expected to be with increasing growth, also subject to greater heavy duty.

The purpose of the investigation was to determine the condition of the asphalt surface course and base, as well as subsurface soil conditions at the site in reference to recommendations for planned surface course milling and overlay of the existing pavement. Improved cross pavement culverts are also planned in certain locations along South Pine Lake Road. New pavement design is based on the obtained results and analysis in this study with some alternate procedures if desired.

II. SUBSURFACE EXPLORATION

1. General / Scope of Work

The proposed project includes the reconstruction of about 4,000 linear feet of existing asphaltic concrete pavement along South Pine Lake Road, South of SH 105 in Conroe, Texas. The scope of the project includes the evaluation of existing asphaltic and base materials, with the intent to mill and overlay all asphalt-bound layers with a new levelling course and surface course. Subgrade stabilization and/or pulverizing base with other binder materials to develop a recommended full replacement pavement section is also an option. Thereafter, we are developing thickness recommendations for the new surface course.

Accordingly, the investigation included reconnaissance of the immediate site, geologic desktop review, boring log preparation, subsurface exploration, field and laboratory testing, with an engineering analysis and evaluation of the subsurface materials. The purpose of this subsurface exploration and analysis was to determine soil profile components, the engineering characteristics of the subsurface materials, and to provide criteria for use by design engineers for designing pavement. Key items to be addressed in this scope, therefore, include:

➢ Existing pavement section sampling and thickness via shallow asphalt/base cores.

➢ Geotechnical soil classification and shear strength determination to 6-feet depth via borings.

➢ Subgrade stabilization and full-depth pavement reclamation requirements.

➢ New pavement section recommendations.

➢ Replacement culvert bedding options.

The exploration and analysis of the subsurface conditions reported herein are considered in sufficient detail and scope to form a reasonable basis for the recommendations. These recommendations are based on available soil information and preliminary project information furnished by City of Conroe Engineering.

Any revision of plans for the proposed pavement from those enumerated in this report should be brought to the attention of the soil engineer, so that he may determine if changes in the recommendations are required. If deviations from the noted subsurface conditions are encountered during construction, they should also be brought to the attention of the soil engineer.

2. Description of the Site

The project alignment along South Pine Lake Road has a rolling topography, from South of SH 105 for about 2,200-feet, then flat up to the end of the project, in Conroe, Texas. The project is approximately 4,000 feet in length comprising an old 2-lane asphaltic concrete pavement. Lake Loraine and Pine Lake lie far to the east. A pond is located on the west of the project line. Plate No. 1 presents a Vicinity Map.

Based on visual observation, the existing pavement exhibited signs of fatigue cracking, longitudinal cracking, transverse cracking, and rutting, possibly related to heavy-duty transit and the existing pavement age and quality, including a limited surface course along the project line. The cracks observed were in the center of the road and near both shoulders. Refer to Plates Nos. 7 and 8 for Photos showing the Existing Pavement Condition and field operations.

Coring revealed 2 to 3½ -inch variable thickness asphaltic concrete, predominantly made of one or two layers. Thereafter, variable base thickness between 9 and 14-inches was sampled. Refer to Section III of the report for more details.

Additionally, the obtained results below pavement layers showed subgrade soil comprised primarily of loose silty sand to the maximum depth of drilling of 6-ft., B-2 through B-4, or sandy lean clay (one location), followed by clayey sand and sandy fat clay, B-1, at the time of drilling operations.

3. Site Geology and Surface Fault

The site geology for the geographic area corresponds to the “Flemming Formation”, with the Tertiary Period, Miocene Epoch or Series1. This formation primarily includes clay, silt, and sand with calcareous concretions. The site is close to the Willis Formation (coastward belt).

Fault assessment was conducted based on current guidelines for Geological Fault Studies contained in the March 1985 Houston Geological Society (HFS) Bulletin. We have reviewed several available published literature sources on faults in the area, including USGS fault maps and site reconnaissance. A cursory review of available surface faulting maps2 revealed that no well-documented principal faults lie within a 1-mile radius of the site.

A detailed surface fault investigation was beyond the scope of this investigation. It should be noted that the coastal plains in this region have complex geology, which includes active surface faulting. Fault activities and signs of fractures/distress related to faulting were not observed at the time of the site reconnaissance.

1 Note: USGS, TNRIS, UTBEG, GEOLOGIC ATLAS OF TEXAS 2 Note: USGS, Verbeek and Clanton (1978), Shah and Lanning-Rush (2005)

4. Field Investigation

The field investigation, completed on April 08, 2026, was performed to determine applicable engineering characteristics of the subsurface materials as related to the pavement, base, and subgrade evaluation, which included a reconnaissance of the project site, drilling exploratory borings, and recovering representative soil samples.

Subsurface soil conditions were explored by advancing and sampling 4 soil test borings located almost 1,000 feet apart, in a “zigzag” pattern, along the east-bound and west-bound lanes of South Pine Lake Road. These were established at locations presented by the City of Conroe Engineering. Soil borings B-1 through B-4 were drilled to a depth of 6-feet below the existing ground surface. Sample depth and description of soil classification (based on the Unified Soil Classification System) are presented on the Soil Boring Logs, Plate Nos. 3 through 6.

In order to evaluate the existing asphaltic pavement condition, GETI initially conducted asphalt / base coring at all four boring locations. Plate No. 2 presents Approximate Boring / Loring Locations whilst Plate Nos. 7 & 8 show Representative Site Photographs.

The soil borings were of 3-inch nominal diameter. Both relatively undisturbed and disturbed soil samples were obtained at 2-feet intervals continuously to a depth of 6-feet. The soil borings were performed with a drilling rig equipped with a rotary head and conventional solid-stem augers used to advance the holes.

Representative disturbed or undisturbed soil samples were obtained employing thin-walled sampling procedures in general accordance with ASTM D1587. Blow counts (if necessary) were obtained in general accordance with ASTM D-1586 Standard Penetration Test (SPT) and Split-Barrel Sampling of cohesionless soil.

Soil samples were identified according to the boring number and depth, and wrapped in aluminum foil and polyethylene plastic wrapping bags to prevent moisture loss and disturbance. All of the samples were transported to our geotechnical laboratory for examination, testing, and analysis. All borings were backfilled after final water readings were obtained, with the soil cuttings accumulated during the drilling operation. Thereafter, cold patch asphalt was used to restore the pavement surface.

4.1 Field Strength Tests

During the boring field operation, samples of the cohesive soil from the thin-walled tube were frequently tested in compression by use of a calibrated soil penetrometer to provide a measure of shear strength and blow counts from the SPT for cohesionless soil, to aid in characterizing the soil consistency.

4.2 Water Level Measurement

The information in this report summarizes conditions as found on the date the borings were drilled.

Ground water was NOT encountered during drilling operations to the maximum drilled depth of 6-feet.

Long-term monitoring of the ground water level was beyond the scope of this study. It should be noted that the ground water table may be expected to fluctuate with environmental variations such as the frequency and magnitude of rainfall and the time of the year when construction begins.

5. Asphalt Core Data

Asphalt cores of the existing pavement were taken at four locations to evaluate the existing surface course and base (if present) materials, using a nominal asphalt core diameter of 4-inches. Core samples were acquired and tested in general accordance with ASTM C42, “Standard Test Method for Obtaining and Testing Drilled Cores and Sawed Beams of Concrete”.

Plate No. 2 presents the attached site plan for approximate coring locations corresponding to the same locations with soil borings (B-1 through B-4). The following tests were performed on representative cores and base materials of the recovered existing surface course and base materials. Results are discussed later, in Section IV.

6. Laboratory Testing

Complementing the field investigation, a supplemental laboratory investigation was conducted to ascertain additional pertinent engineering characteristics of the subsurface materials and asphalt cores necessary in analyzing their behavior under the proposed loading/traffic conditions. During the laboratory investigation, all field soil samples from the borings were examined and classified by a soil engineer.

Laboratory tests were then performed on selected soil/asphalt core samples to evaluate and determine the physical and engineering properties of the soils in accordance with prescribed ASTM/TxDOT standards and methods. The following laboratory tests were performed:

LABORATORY TEST TEST STANDARD

Moisture Content of Soils ASTM D2216

Moisture Content and In Situ Dry Density of Soils ASTM D2937

Percent Soil Particles Passing No. 200 Sieve ASTM D1140

Particle Size Analysis – Sieve Analysis and Hydrometry Test ASTM D421 & 422

Liquid Limit, Plastic Limit, and Plasticity Index of Soils ASTM D4318

The tests noted above were performed to establish the index properties and to aid in the proper classification of the subsurface soils. Plate Nos. 3 through 6 presents the test results which are shown on the Soil Boring Logs. Appendix A presents the Asphalt Core Pictures from the existing surface course. There was no base. The asphalt cores were tested for:

LABORATORY TEST TEST STANDARD

Determination of Asphalt Content by Ignition TEX-236-F

Theoretical Max. Specific Gravity of Bituminous Mixtures TEX-227-F

Bulk Specific Gravity of Compacted Bituminous Mixtures TEX-207-F

Sieve Analysis of Fine and Coarse Aggregates TEX-200-F

The asphalt cores test results are presented and discussed in Section IV of this report.

III. GENERAL DESCRIPTION OF SUBSURFACE MATERIALS

1. General Stratigraphy

The specific subsurface stratigraphy, beneath existing pavement and base, as determined by the field exploration at individual boring locations, is shown in detail on the soil boring logs attached to this report.

However, the stratigraphy can be generalized as follows:

STRATUM

NUMBER

RANGE

OF

DEPTH,

Ft.

BORING

NUMBER

SOIL DESCRIPTION

(below the existing pavement system)

I 0 – 2’ B-1 Very stiff, brown, and dark brown SANDY LEAN CLAY (CL)*

II 0 – 6’ B-2, B-3, & B-4 Loose, reddish-tan, dark brown, and tan SILTY SAND (SM)*

III 2 – 4’ B-1 Soft to firm, brown CLAYEY SAND (SC)*

IV 4’ – 6’ B-1 Firm to stiff, dark gray SANDY FAT CLAY (CH)*

* Classification is in accordance with the Unified Soil Classification System and TEX-141E

Laboratory test results for the soils sampled indicate that the Liquid Limits range from 18 to 56 percent, the Plasticity Indices range from 3 to 33, and the soil moisture content ranged from 5 to 24 percent. The borings indicate the significant presence of silty sand in three of the four, with low to non-plastic fines.

According to the obtained results as provided above, the surface soil below pavement layers comprised primarily loose silty sand to the maximum depth of drilling of 6-ft., B-2 through B-4, or sandy lean clay (one location), followed by clayey sand and sandy fat clay, B-1, at the time of drilling operations..

2. Swell Potential

Based on plasticity index results, the sandy lean clay, clayey sand, and sandy fat clays are characterized as having low to moderate shrink/swell potential. Silty sand has negligible to low shrink/swell potential.

When the moisture content of clay soil increases, the volume increases; conversely, when the moisture content of this type of soil decreases, the soil volume decreases. Volume changes can result in movement and pavement distress.

3. Potential Vertical Rise (PVR)

Magnitude of the moisture -induced vertical movement, potential vertical rise, was calculated using the Texas Department of Transportation Method Tex-124-E in conjunction with our evaluation of the current moisture profile. Potential vertical rise (PVR) across the location of the proposed pavement is estimated to be mainly between ½ to ¾ -inch. More movement will occur in areas where the soil dries, and water subsequently ponds during or after construction. Site grading may also influence the potential for movement.

4. Near Surface Moisture Retentive Soil

Silty sand soil is present in the site, where the base might have been previously. These soils have a strong potential for moisture retention and pumping during site development, cut / fill operations, placement, and compaction efforts thereafter. These are also particularly prone during the rainy season, and special care or treatment is required.

Substantial drainage measures during construction are often essential. Soil stabilization for subgrade improvement and constructability measures may often be required. Drainage measures during construction may be dependent on the season and should be planned for any cut and fill operations.

Strategic use of trenches, sumps, and pumps would be prudent during the rainy season.

5. Existing Pavement Thickness

The surface of the roadways in this study was covered with an existing 2 to 3½-inch variable thickness asphaltic concrete, predominantly made of one or two layers, over 9 to 14 inches of loose or compacted base materials.

The following table provides the approximate thickness of encountered pavement systems at four core and boring locations (B-1 through B-4), which were measured during drilling operations.

CORING NO. ASPHALT

PAVEMENT

THICKNESS, IN.

1st. Layer

ASPHALT

PAVEMENT

THICKNESS, IN.

2nd. Layer

UNDERNEATH

SUBGRADE

THICKNESS, IN.

UNDERNEATH

SUBGRADE TYPE

B-1 2 - 14 Base

B-2 1 2½ 13 Base

B-3 2½ - 10 Base

B-4 2½ - 9 Base

Note: The asphalt layers were almost the same material. Photos of the pavement cores and their measurements are illustrated in Appendix A of this report. The asphalt thicknesses are also provided as a note in boring/coring logs, Plate Nos. 3 to 6, as well.

IV. EXISTING PAVEMENT EVALUATIONS AND RECOMMENDATIONS

Based on visual observation, the existing pavement exhibited signs of fatigue cracking, longitudinal cracking, transverse cracking, and rutting, possibly related to heavy-duty traffic and the existing pavement age and quality, including a limited surface course along the project line. The cracks observed were in the center of the road and near both shoulders. Some pictures are presented in the appendices of this report associated with the existing pavement conditions.

GETI understands that the existing surface course, which consists of 2 to 3½ -inch variable thickness asphaltic concrete, predominantly made of one or two layers, over 9 to 14 inches of loose or compacted base materials.

1. Evaluation of Existing Asphalt Pavement

Three composite asphalt samples were made by mixing the four asphalt cores sampled along the existing pavement for evaluation of the asphalt content, bituminous mixtures, and gradation of the fine and coarse aggregates encountered in the surface course.

1.1 Asphalt Content and Bituminous Mixtures

Asphalt core samples obtained from the existing pavement were tested in the GETI laboratory to estimate the amount of asphalt content, specific gravity, and density of the bituminous materials. As mentioned earlier, the asphalt pavement encountered was mainly composed of one or two layers with almost the same materials categorized as Type D Surface Course.

Three representative composite samples were made and tested by combining multiple cores for the first (top) asphalt layer, the second (bottom) asphalt layer, and the Type D asphalt only.

Asphalt content for the four composite samples (4 cores) ranged from 4.1 to 4.3 percent. Specific gravity ranged from SG = 2.504 to 2.531. Average specimen relative density ranged from approximately 90.20 to

93.7 percent.

Specific test data details are recorded in the following table.

First (top) Asphalt Layer

Sample No. # 1

Cores No. B-1, B-2, B-3, B-4

Asphalt Type Type D

Asphalt Content (%) 4.2

Avg. Actual Specific Gravity 2.518

Avg. Specimen Density (%) 91.07

1.2 Gradation

(a) Gradation of the asphalt cores based on Tex-200-F was performed using the two composite samples of all 4 cores. The results are tabulated below:

1st Layer Asphalt, Sample No. 1

SIEVE ANALYSIS OF FINE AND COARSE AGGREGATES (Tex-200-F)

Sieve Size Total % Passing Master Gradation Limits (TxDOT 341)

Type D, Fine Surface Sample #1

3/4" 100.0 100%

1/2" 100.0 98-100%

3/8" 98.0 85-100%

#4 58.9 50-70%

#8 39.1 35-46%

#30 26.8 15-29%

#50 19.8 7-20%

#200 4.7 2-7%

1st Layer Asphalt, Sample No. 2

SIEVE ANALYSIS OF FINE AND COARSE AGGREGATES (Tex-200-F)

Sieve Size Total % Passing Master Gradation Limits (TxDOT 341)

Type D, Fine Surface Sample #2

3/4" 100.0 100%

1/2" 100.0 98-100%

3/8" 98.2 85-100%

#4 63.4 50-70%

#8 41.9 35-46%

#30 27.9 15-29%

#50 20.6 7-20%

#200 4.8 2-7%

Gradation results for the recovered aggregates from the asphalt cores indicate that samples tested meet the requirement of Item 341, TxDOT Standard Specification for Construction and Maintenance of Highways, Streets, and Bridges 2014.

2. Suitability for Re-Use

GETI encountered approximately 2 to 3½ -inch variable-thickness asphaltic concrete pavement in most of the locations cored along the project line on Old Houston Road. Whilst gradations obtained from cores depict them as satisfactory. Moreover, additional thickness is also required, as described in the next section.

Existing Surface Course can be pulverized, mixed, and treated with additional cement as specified by TXDOT Standard Specification for Construction and Maintenance of Highways, Streets, and Bridges 2014 Item 275. Reworking existing subgrade materials with or without asphaltic concrete pavement is governed by TXDOT Standard Specification for Construction and Maintenance of Highways, Streets, and Bridges 2014 Item 251.

LEFT BLANK INTENTIONALLY

V. PAVEMENT RECOMMENDATIONS

The project consists of the reconstruction of South Pine Lake Road, South of SH 105 in Conroe, Texas. Two scenarios were considered for this roadway, namely:

1. Mill and overlay the existing pavement surface course, with level up course and new surface course, without any additional base or subgrade treatment. This minimum application would require further milling and overlay work in about 10 years.

2. Rehabilitation of the existing pavement structure with milled surface course, pulver mixed with existing base (8-inches depth minimum), both stabilized with 10% cement. Additional level up course and surface course would complete the new paving section, for a projected life of around 20 years, with milling and overlay potentially around 15 years life stage.

The project line along South Pine Lake Road includes around 4,000 lf. of two-lane undivided asphalt pavement (with shallow side drainage ditches and a few cros culverts) starting some 1,000 feet south of SH 105 beyond a four lane, then three lane concrete pavement section. Average Daily Traffic (ADT) counts are limited to two counts by TxDOT in 2021. The inference is that traffic usage, pavement ESALs, and general traffic are projecting growth which will include further heavy-duty vehicles, also subject to increasing growth. Hence, AASTHO pavement design guidelines are followed.

The most recent traffic counts (2021) for South Pine Lake Road near SH 105 are 1,424 AADT and thereafter 1125 AADT toward the southern extent of this project.

18-kip Equivalent Single Axle Loads (ESALs) for 20-year asphaltic concrete pavement life determined or translated from the measured AADTs are as therefore as follows:

Location AADTs Design ESALs

South Pine Lake Road 1,500 0.5 to 0.75 x 106

Note:

Percentage of trucks ~ 5% Annual truck volume growth ~ 2.5 to 5.0%.

GETI evaluated the proposed flexible asphalt pavement improvement comprising two options above.

Option 1 assumes milled pavement with placement of level up course and new surface course, absent any subgrade or base treatment. Option 2 involves milling of the entire existing surface course, and thereafter pulver mixing with existing base materials for a total depth of 8-inches. These materials are pulver mixed together then enriched with 10 percent cement. Both options may require milling and overlay later in their lives, as shown earlier.

1. Flexible Pavement

GETI utilized the 1993 AASHTO Empirical Equation for Flexible Pavement to determine the thickness of the asphaltic pavement.

Input Parameters:

ZR = -1.645 for 95% Reliability

S0 = 0.4

Design ESALs for 20 years (W18) = 0.75 million

Design Life without overlay = 20 years

ΔPSI = Initial Serviceability Index – Final Serviceability Index = 4.4 – 2.5 = 1.9

Where:

ZR is the Standard Normal Deviate that is a function of Reliability.

Reliability is defined as 95% at the corresponding ZR = -1.645.

SO is the Combined Standard Error in predicting pavement serviceability.

W18 is the number of Equivalent 18-kip Single Axle Loads ESALs that will result in a change in serviceability of ΔPSI.

ESAL Calculation Parameters

Design Life = 20 Years

Directional Distribution Factor = 50%

Design Lane Distribution Factor = 100%

Truck Volume Growth Rate = 2.5 to 5.0%

Percent Trucks = 5%

Materials for Use

Subgrade Soil Under Stabilized Soil: Pavement subgrade with MR = 3,000 psi, based on CBR ~ 3

Recycled Surface Course and Cement Stabilized Base: Stabilized material with MR = 50,000 psi. Stabilize existing pavement surface course asphalt-bound layers, and base to a depth 8-inches. TxDOT Item 275 Cement Treatment (Road Mixed) governs this process. We recommend 10 percent cement by volume.

Spread stabilized materials to achieve a uniform thickness across new pavement section. Compact to at least 95 percent of Modified Proctor maximum dry density (ASTM D1557) at a moisture content ranging from optimum to +/- 3 percent of optimum.

Crushed Concrete/ Crushed Limestone: Base material with MR = 50,000 psi, Crushed concrete/limestone base material criteria are defined by TxDOT Item 247. The crushed aggregate base shall be compacted to at least 95 percent of Modified Proctor maximum dry density (ASTM D1557) at a moisture content ranging from optimum to +/- 3 percent of optimum.

Level Up Course: TxDOT level-up course with MR = 350,000 psi, involves the placement of a thin, variable-thickness asphalt layer over existing pavement to correct ruts, depressions, and distortions, thereby restoring proper grade, cross-section, and ride quality. It is often used as surface preparation before resurfacing or as a final layer, commonly executed via blade or laydown methods. Consists of a compacted mixture of mineral aggregate and asphaltic material, similar to hot-mix asphalt concrete, defined by TxDOT Item 7053 Special.

Hot-Mix Asphaltic Concrete: TxDOT surface course with MR = 5000,000 psi, defined as pavement surface course material. Dense Graded Hot Mix Asphaltic Concrete Surface Course should be plant-mixed, hot-laid Type "D": (Dense Graded Surface Course) and meet the requirements specified in TxDOT Item 340 / 341 Hot Mixed-Hot Laid Asphaltic Concrete.

1.1 Mill and Overlay Existing Asphalt Pavement.

Pavement Component MR, (psi) W18 ESALs for

ΔPSI

Recommended Design

Pavement Thickness (inches)

Surface Hot-Mix Asphaltic Concrete (TXDOT Item 340, Type D)

500,000

0.75 x 106

(20-years)

2.5 to 3-inches

Level Up Course Hot Mix Asphaltic Concrete (TxDOT Item 7053 Special

350,000 1.0 to 1.5-inches

Minimum combined thickness of Surface + Level Up Course ~ 4-inches minimum, to be determined by the actual required Level Up Course thickness.

1.2 Mill Existing Asphalt Pavement, Pulver Mix with Existing Subgrade and Stabilize.

Pavement Component MR, (psi) W18 ESALs for

ΔPSI

Recommended Design

Pavement Thickness (inches)

Surface Hot-Mix Asphaltic Concrete (TXDOT Item 340, Type D)

500,000

0.75 x 106

(20-years)

2.5 to 3.0-inches

Level Up Course Hot-Mix Asphaltic Concrete (TxDOT Item 7053 Special)

350,000 1.0 to 1.5-inches

Pulver Mixed Milled Materials and Stabilized Base

(TxDOT Item 275) 15,000 8-inches

GETI recommends Type D Dense Graded Hot Mix Asphaltic Concrete as surface course, as well as a level up course. Approved base and subbase material, if required, shall be spread and uniformly compacted to 95% Modified Proctor Density (ASTM 1557) prior to commencing surfacing.

GETI recommends the existing asphaltic surface course be milled completely ranging from 3 to 6 inch, and pulverized, mixed with crushed concrete base (imported), and recycled by pulverizing and mixing with cement additive (10 percent minimum); then spread equally across both the existing 2-lane pavement or shoulders as well.

GETI recommends the existing asphaltic surface course be temporarily stockpiled, for use later according to the construction sequence.

1.3 Pavement Coatings

Seal Coat: Seal coat is a thin uppermost surface treatment used to waterproof the surface and to provide skid resistance. TxDOT Item 316 defines the application of Seal Coat.

Tack Coat: Tack coat is a very light application of asphalt, usually asphalt emulsion diluted with water. It provides proper bonding between two layers of binder course and must be thin, uniformly cover the entire surface, and set very fast. TxDOT Item 300 defines the application of Tack Coat. Use of a tack coat will depend on the design thickness of binder courses and the number layers deemed necessary to achieve the desired compaction.

LEFT INTENTIONALLY BLANK

VI. DRAINAGE DITCHES AND CULVERTS

1. Drainage Ditches

Roadway drainage ditch side slopes should be graded at a maximum 4:1 (horizontal:vertical) with topsoil and seeding established as soon as possible after pavement construction completion.

2. Culvert Crossings

Culvert crossing replacements perpendicular to the pavement direction should be bedded in CSS 1.5 to

2.0 sack per ton, with at least 12-inches CSS beneath the pipe flow line and at least 12-inches CSS crown above the pipe and beneath the underside of the pavement section.

CSS should be compacted to at least 95 percent of ASTM D558, and at a moisture content which does not exceed 12.5 percent.

LEFT INTENTIONALLY BLANK

VII. GENERAL CONSTRUCTION CONSIDERATIONS

1. Site Preparation

1.1 In general, remove all vegetation, tree roots, organic topsoil, and any undesirable materials from the construction area. Tree trunks and roots under paved areas should be removed to a root size of less than ½-inch. We recommend that the stripping depth be evaluated at the time of construction by a soil technician.

1.2 Any on-site fill soils, encountered in the structure areas during construction, must have records of successful compaction tests signed by a registered professional engineer that confirms the use of the fill and record of construction and earthwork testing. These tests must have been performed on all the lifts for the entire thickness of the fill. If no compaction test results are available, the fill soil must be removed, processed, and re-compacted in accordance with our recommendations of “Structural Fill and Subgrade Preparation”.

1.3 We recommend that the site and soil conditions used in the structural design be verified by the engineer’s site visit after all the earthwork and site preparation has been completed prior to the pavement placement.

2. Structural Fill and Subgrade Preparation

2.1 The site should be stripped to suitable depth and miscellaneous fill material. The exposed subgrade surface should then be proof rolled. All soft or loose soils should be removed and replaced with select fill materials.

2.2 Structural Select Fill should consist of a clean Sandy Clay with Liquid Limit (LL) less than 35 percent and a Plasticity Index (PI) between 10 and 20. Specifications should require uniform thickness throughout the paved area.

2.4 Structural Select Fill material should be placed in a maximum of 8-inch loose lift and compacted to a minimum of 95 percent of the maximum dry density as per ASTM D698. The moisture content should be between +1% to +3% of optimum moisture.

2.5 In cut areas, the soils should be excavated to grade, and the surface soils proof rolled and scarified to a minimum depth of 6-inches and recompacted to the previously mentioned density tests at the time of construction.

3. Surface Drainage and Erosion Control

It is recommended that site drainage be well developed. Surface water should be directed away from the subgrade soils. No ponding of surface water should be allowed. Swales can be used to control surface water from flowing over sloped pond banks. In conjunction with vegetation, geotextile systems are effective in controlling or mitigating bank erosion.

VIII. DISCLAIMER

The information and recommendations contained in the report summarize conditions found at the site of the Proposed City of Conroe Street Rehabilitation and Drainage located at South Pine Lake Road, South of SH 105 in Conroe, Texas, specified, and on the date the field exploration was completed. The attached soil boring logs are a true representation of the soils encountered at the stratigraphy as found during the field exploration and drilling of the subject site.

Reasonable variations from the subsurface information presented in this report are assumed. If conditions encountered during construction are significantly different than those presented in this report, GETI should be notified immediately.

The report was prepared for the sole and exclusive use by our client, based on specific and limited objectives. GETI assumes no responsibility or obligation for the unauthorized use of this report beyond the stated project objectives and work limitations. In addition, the construction process may itself alter site soil conditions. Therefore, experienced geotechnical personnel should observe and document the construction procedures and all conditions encountered. We recommend that the owner retain Geoscience Engineering and Testing, Inc. to provide this service, as well as the construction material and testing, and inspection required during the construction phase of the project.

The standard of care for all professional engineering and related services performed by Geoscience Engineering & Testing, Inc. (GETI) corresponds to other geotechnical firms under similar circumstances in the project locality. GETI makes no warranties, express or implied, under this agreement or about any services performed or furnished by us.

The following illustrations are attached to complete this report:

ILLUSTRATIONS PLATE NUMBERS

Vicinity Map 1

Soil Boring Plan 2

Boring Logs 3 through 6

Site Pictures 7 and 8

Obtained Pavement Core Pictures Appendix A

Vicinity Map

GEOTECHNICAL EXPLORATION AND PAVEMENT SUBGRADE EVALUATION

Proposed City of Conroe Street Rehabilitation and Drainage

South Pine Lake Road, South of SH 105 Conroe, Texas

GETI NO: 26G13427

PLATE NO.: 1a

N

Project Line

Proposed City of Conroe Street Rehabilitation and Drainage

South Pine Lake Road, South of SH 105 Conroe, Texas

GETI NO: 26G13427

PLATE NO.: 1b

Approximate Boring Locations

Proposed City of Conroe Street Rehabilitation and Drainage

South Pine Lake Road, South of SH 105 Conroe, Texas

GETI NO: 26G13427

NOT TO SCALE PLATE NO.: 2

B-1

B-2

B-3 B-4

CL

SC

CH

P=3.0

P=0.50

P=1.0

SANDY LEAN CLAY (CL), brown and dark brown, very stiff

CLAYEY SAND (SC), brown, soft to firm

SANDY FAT CLAY (CH), dark gray, firm to stiff

Boring terminated at 6'

Northing:3362547.59 Easting:246974.79

LOG OF BORING B-1

Site is relatively flat. Boring coordinates and elevation obtained from Google

Earth. Asphalt Pavement Thickness: 2", Base Thickness: 14"

N P T Cu

SS

F

IE

LD

S T

R E

N G

T H

D A

T A

U U

S H

E A

R

S T

R E

N G

T H ts f)

C O

N F

IN

IN

G P

R E

S S

U R

E ps i)

P A

S S

IN

G

S

IE

V

E

Shelby Tube

Measured: Perched:

DATE

SURFACE ELEVATION

SS (tsf)

Torvane (psf)

Sample Key:

Water Observations:

LOCATION

PI200 400 600 800

W A

T E

R L

E V

E L

USCS Plastic Limit

Moisture Content

1.0 2.0 3.0 4.0

D E

P T

H ft.

20 40 60 80D R

Y D

E N

S

IT

Y pc f)

M O

IS

T

U R

E C

O N

T E

N T

PROJECT:

26G13427 Dry Auger 0 to 6'PROJECT NO.: BORING TYPE:

BLOW COUNT

P

LA

S T

IC

IT

Y

IN

D E

X

Liquid Limit

ATTERBERG

LIMITS(%)

E S

T

IM

A T

E D

A N

G

LE

O F

IN

T

E R

N A

L F

R

IC

T

IO

N

O T

H E

R T

E S

T S

R

E M

A R

K S

LL

1.0 2.0 3.0 4.0

F A

IL

U

R E

S T

R A

IN

Cu (tsf)

P

LA

S T

IC

L

IM

IT

PL

Est.: Key to Abbreviations:

SPT

S A

M P

LE

S

Plate No. 3

Water Level

Disturbed

232.0

- SPT Data (Blows/Ft)

- Pocket Penetrometer (tsf)

- Torvane (psf)

- Undrained Cohesion (tsf)

- Shear Strength (P/2, tsf)

MATERIAL DESCRIPTION

Natural Moisture Content and

Atterberg Limits

LI

Q

U

ID

L

IM

IT

Proposed City of Conroe Street Rehabilitation and Drainage South Pine Lake Road, South of SH 105, Conroe, Texas

04/08/2026

Notes:

4 8 12 16

HCFCD 13427.GINT LOG.GPJ 4/28/26

ideh golrokh Stamp

18 15 3 33

30 Non-Plastic

SM

SM

B

N=8

N=7

SILTY SAND (SM), reddish-tan

SILTY SAND (SM), dark brown, loose

Boring terminated at 6'

Northing:3362138.23 Easting:247085.52

LOG OF BORING B-2

N P T Cu

SS

F

IE

LD

S T

R E

N G

T H

D A

T A

U U

S H

E A

R

S T

R E

N G

T H ts f)

C O

N F

IN

IN

G P

R E

S S

U R

E ps i)

P A

S S

IN

G

S

IE

V

E

Shelby Tube

Measured: Perched:

DATE

SURFACE ELEVATION

SS (tsf)

Torvane (psf)

Sample Key:

Water Observations:

LOCATION

PI200 400 600 800

W A

T E

R L

E V

E L

USCS Plastic Limit

Moisture Content

1.0 2.0 3.0 4.0

D E

P T

H ft.

20 40 60 80D R

Y D

E N

S

IT

Y pc f)

M O

IS

T

U R

E C

O N

T E

N T

PROJECT:

26G13427 Dry Auger 0 to 6'PROJECT NO.: BORING TYPE:

BLOW COUNT

P

LA

S T

IC

IT

Y

IN

D E

X

Liquid Limit

ATTERBERG

LIMITS(%)

E S

T

IM

A T

E D

A N

G

LE

O F

IN

T

E R

N A

L F

R

IC

T

IO

N

O T

H E

R T

E S

T S

R

E M

A R

K S

LL

1.0 2.0 3.0 4.0

F A

IL

U

R E

S T

R A

IN

Cu (tsf)

P

LA

S T

IC

L

IM

IT

PL

Est.: Key to Abbreviations:

SPT

S A

M P

LE

S

Plate No. 4

Water Level

Disturbed

240.0

- SPT Data (Blows/Ft)

- Pocket Penetrometer (tsf)

- Torvane (psf)

- Undrained Cohesion (tsf)

- Shear Strength (P/2, tsf)

MATERIAL DESCRIPTION

Natural Moisture Content and

Atterberg Limits

LI

Q

U

ID

L

IM

IT

Proposed City of Conroe Street Rehabilitation and Drainage South Pine Lake Road, South of SH 105, Conroe, Texas

Site is relatively flat. Boring coordinates and elevation obtained from Google

Earth. Asphalt Pavement Thickness: 3.5", Base Thickness: 13"

B - Bag Sample

04/08/2026

Notes:

4 8 12 16

HCFCD 13427.GINT LOG.GPJ 4/28/26

17 Non-Plastic

SM

B

N=6

N=8

SILTY SAND (SM), tan

- loose from 2' to 6'

Boring terminated at 6'

Northing:3361830.83 Easting:247104.83

LOG OF BORING B-3

N P T Cu

SS

F

IE

LD

S T

R E

N G

T H

D A

T A

U U

S H

E A

R

S T

R E

N G

T H ts f)

C O

N F

IN

IN

G P

R E

S S

U R

E ps i)

P A

S S

IN

G

S

IE

V

E

Shelby Tube

Measured: Perched:

DATE

SURFACE ELEVATION

SS (tsf)

Torvane (psf)

Sample Key:

Water Observations:

LOCATION

PI200 400 600 800

W A

T E

R L

E V

E L

USCS Plastic Limit

Moisture Content

1.0 2.0 3.0 4.0

D E

P T

H ft.

20 40 60 80D R

Y D

E N

S

IT

Y pc f)

M O

IS

T

U R

E C

O N

T E

N T

PROJECT:

26G13427 Dry Auger 0 to 6'PROJECT NO.: BORING TYPE:

BLOW COUNT

P

LA

S T

IC

IT

Y

IN

D E

X

Liquid Limit

ATTERBERG

LIMITS(%)

E S

T

IM

A T

E D

A N

G

LE

O F

IN

T

E R

N A

L F

R

IC

T

IO

N

O T

H E

R T

E S

T S

R

E M

A R

K S

LL

1.0 2.0 3.0 4.0

F A

IL

U

R E

S T

R A

IN

Cu (tsf)

P

LA

S T

IC

L

IM

IT

PL

Est.: Key to Abbreviations:

SPT

S A

M P

LE

S

Plate No. 5

Water Level

Disturbed

277.0

- SPT Data (Blows/Ft)

- Pocket Penetrometer (tsf)

- Torvane (psf)

- Undrained Cohesion (tsf)

- Shear Strength (P/2, tsf)

MATERIAL DESCRIPTION

Natural Moisture Content and

Atterberg Limits

LI

Q

U

ID

L

IM

IT

Proposed City of Conroe Street Rehabilitation and Drainage South Pine Lake Road, South of SH 105, Conroe, Texas

Site is relatively flat. Boring coordinates and elevation obtained from Google

Earth. Asphalt Pavement Thickness: 2.5", Base Thickness: 10"

B - Bag Sample

04/08/2026

Notes:

4 8 12 16

HCFCD 13427.GINT LOG.GPJ 4/28/26

25 Non-Plastic

Non-Plastic

SM

SM

N = 4

N = 7

N = 7

SILTY SAND (SM), dark brown, very loose to loose

SILTY SAND (SM), tan, loose

Boring terminated at 6'

Northing:3361517.53 Easting:247101.21

LOG OF BORING B-4

Site is relatively flat. Boring coordinates and elevation obtained from Google

Earth. Asphalt Pavement Thickness: 2.5", Base Thickness: 9"

N P T Cu

SS

F

IE

LD

S T

R E

N G

T H

D A

T A

U U

S H

E A

R

S T

R E

N G

T H ts f)

C O

N F

IN

IN

G P

R E

S S

U R

E ps i)

P A

S S

IN

G

S

IE

V

E

Shelby Tube

Measured: Perched:

DATE

SURFACE ELEVATION

SS (tsf)

Torvane (psf)

Sample Key:

Water Observations:

LOCATION

PI200 400 600 800

W A

T E

R L

E V

E L

USCS Plastic Limit

Moisture Content

1.0 2.0 3.0 4.0

D E

P T

H ft.

20 40 60 80D R

Y D

E N

S

IT

Y pc f)

M O

IS

T

U R

E C

O N

T E

N T

PROJECT:

26G13427 Dry Auger 0 to 6'PROJECT NO.: BORING TYPE:

BLOW COUNT

P

LA

S T

IC

IT

Y

IN

D E

X

Liquid Limit

ATTERBERG

LIMITS(%)

E S

T

IM

A T

E D

A N

G

LE

O F

IN

T

E R

N A

L F

R

IC

T

IO

N

O T

H E

R T

E S

T S

R

E M

A R

K S

LL

1.0 2.0 3.0 4.0

F A

IL

U

R E

S T

R A

IN

Cu (tsf)

P

LA

S T

IC

L

IM

IT

PL

Est.: Key to Abbreviations:

SPT

S A

M P

LE

S

Plate No. 6

Water Level

Disturbed

275.0

- SPT Data (Blows/Ft)

- Pocket Penetrometer (tsf)

- Torvane (psf)

- Undrained Cohesion (tsf)

- Shear Strength (P/2, tsf)

MATERIAL DESCRIPTION

Natural Moisture Content and

Atterberg Limits

LI

Q

U

ID

L

IM

IT

Proposed City of Conroe Street Rehabilitation and Drainage South Pine Lake Road, South of SH 105, Conroe, Texas

04/08/2026

Notes:

4 8 12 16

HCFCD 13427.GINT LOG.GPJ 4/28/26

Site Reconnaissance/Existing Road Conditions

Project No.: 26G13427

PLATE NO.: 7

Coring/Drilling Operation

Project No.: 26G13427

PLATE NO.: 8

Appendix A

Pavement Cores Pictures

C-1 C-2

C-3 C-4

Appendix A-1