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HomeMy WebLinkAboutBLOOM FILING FOUR - FDP240001 - SUBMITTAL DOCUMENTS - ROUND 1 - SUPPORTING DOCUMENTATION (8) CTL|Thompson, Inc. Denver, Fort Collins, Colorado Springs, Glenwood Springs, Pueblo, Summit County – Colorado Cheyenne, Wyoming and Bozeman, Montana Bloom Subdivision Filing 1 Roads, Phase 3 Donella Drive, and Portions of Aria Way, Delozier Road, and International Boulevard Fort Collins, Colorado Prepared for: HARTFORD HOMES 4801 Goodman Street Timnath, Colorado 80542 Attention: Shane Westlind Vice President of Land CTL|T Project No. FC07733.010-135 October 25, 2023 SUBGRADE INVESTIGATION AND PAVEMENT RECOMMENDATIONS Table of Contents Scope 1 Summary Of Conclusions 1 Site Location and Project Description 2 Previous Investigations 2 Field and Laboratory Investigation 2 Subsurface Conditions 3 Pavement Design 3 Traffic Projections 4 Subgrade and Groundwater Conditions 4 Pavement Thickness Calculations 5 Pavement Recommendations 5 Subgrade and Pavement Materials and Construction 6 Water-Soluble Sulfates 7 Maintenance 8 Surface Drainage 9 Limitations 9 FIGURE 1– LOCATIONS OF EXPLORATORY BORINGS FIGURES 2 AND 3 – SUMMARY LOGS OF EXPLORATORY BORINGS APPENDIX A – RESULTS OF LABORATORY TESTING APPENDIX B – PAVEMENT DESIGN CALCULATIONS APPENDIX C – PAVEMENT CONSTRUCTION RECOMMENDATIONS APPENDIX D – MAINTENANCE PROGRAM HARTFORD HOMES BLOOM FILING 1 ROADS - PHASE 3 CTL  T PROJECT NO. FC07733.010-135 1 Scope This report presents the results of our subgrade investigation and pavement recommendations for the proposed Phase 3 roadways in Filing 1 of the Bloom Subdivision in Fort Collins, Colorado. The purpose of our subgrade investigation was to determine the subsurface conditions and to evaluate pavement support characteristics for our pavement recommendations. The report was conducted in general conformance with the Larimer County Urban Area Street Standards, August 2021. This report was prepared from data developed during field exploration, laboratory testing, engineering analysis, and experience with similar conditions. The report includes a description of the subsurface conditions found in exploratory borings, laboratory test results, and pavement construction and material recommendations for the construction of Donella Drive and portions of Aria Way, Delozier Road, and International Boulevard. If plans change significantly, we should be contacted to review our investigation and determine if our recommendations still apply. A brief summary of our conclusions is presented below, with more detailed criteria and recommendations contained in the report. Summary Of Conclusions 1. Soils encountered in our borings generally consisted of 10 feet of clean to clayey, gravelly sand or sandy clay. The upper 3 to 10 feet of all but one boring was fill, placed during site grading and/or utility installation. Bedrock was not encountered during this investigation. Groundwater was encountered in one boring at approximately 8 feet. 2. The subgrade soils classified as A-4 to A-6 according to AASHTO methods. Such material is considered to exhibit good to poor subgrade support. Swell- consolidation testing indicated swells of up to 3.5 percent. Mitigation for swelling soils will be required. 3. Precipitation in the area was observed to create soft, saturated soil conditions. If soft soils are encountered during construction stabilization can likely be achieved by crowding 1½ to 3-inch nominal size crushed rock into the subgrade until the base does not deform by more than about 1-inch under compactive effort. Chemical treatment (cement, fly ash, lime) can also be considered for stabilization. We understand that cement stabilization has been the preferred method at this site. Soft soil mitigation is discussed in the report. HARTFORD HOMES BLOOM FILING 1 ROADS - PHASE 3 CTL  T PROJECT NO. FC07733.010-135 2 4. Asphaltic concrete and/or Portland cement concrete over aggregate base course are appropriate surface pavements for the included roadways. Minimum pavement recommendations are presented in this report. Site Location and Project Description The Bloom Subdivision is located between East Vine Drive and Mulberry Street, east of Timberline Drive in Fort Collins, Colorado (Figure 1). Phase 3 includes portions of Aria Way, Delozier Road, and International Boulevard. Also included in the investigation is Donella Drive. The roads are anticipated to be paved with hot mix asphalt and/or Portland cement concrete. Previous Investigations CTL|Thompson previously performed a Preliminary Geotechnical Investigation at Bloom Subdivision under CTL|T project No. FC07733-115, report dated May 11, 2017, and a Geotechnical Investigation for various Filing 1 structures under FC07733.005-125 dated July 18, 2023. A Subgrade Investigation and Pavement Design was performed for the Phase 1 and 2 roads under CTL|T Project Nos. FC07733.006-135 and FC07733.008-135 reports dated July 26, 2023 and September 25, 2023 respectively. Data from the previous investigations were considered for this report. Field and Laboratory Investigation Our field investigation consisted of drilling eight borings to a depth of approximately 10 feet, logging the subsurface conditions, recording penetration-resistance tests, and acquiring samples of the subgrade materials. Borings were drilled at approximate 500-foot spacing, or less. The approximate locations of our borings are presented on Figure 1. The borings were drilled with 4-inch diameter continuous-flight augers and a truck-mounted drill. Our field representative directed the field investigation as the borings were advanced. Bulk samples were obtained from the upper 4 feet of the borings and modified California samples were obtained from selected intervals within the borings. The number of blows from a 140-pound hammer falling 30 inches, required to drive the modified California sampler, were recorded. Summary logs of the borings, including results of field penetration resistance tests, are presented on Figures 2 and 3. HARTFORD HOMES BLOOM FILING 1 ROADS - PHASE 3 CTL  T PROJECT NO. FC07733.010-135 3 After the samples were returned to our laboratory, our geotechnical engineer for this project examined the samples and assigned laboratory testing. Laboratory testing was performed in general accordance with AASHTO and ASTM methods to determine index properties, classification, and subgrade support values for those soil types influencing the pavement design. To evaluate potential heave, swell-consolidation testing was performed on samples of the subgrade soils. Swell-consolidation test samples were tested under a pressure of 150 psf per LCUASS standards. Other laboratory tests and analysis included moisture content, dry density, Atterberg limits, gradation analysis, swell-consolidation, particle-size analysis, and water-soluble sulfate tests. We performed two Hveem stabilometer tests on bulk samples during this investigation. Results of laboratory tests are presented on Appendix A and summarized in Table A-I. Subsurface Conditions Soils encountered in our borings generally consisted of clean to clayey, gravelly sand or sandy clay to the depths explored of 10 feet. The upper 3 to 10 feet of all but one boring was identified as fill comprised of sandy clay or clayey sand, placed during site grading and/or utility installation. The fill was tested by our firm and generally found to meet project specifications at the time of placement. Bedrock was not encountered during this investigation. Swell- consolidation testing of the upper 5 feet indicated 1.1 percent compression and 0.4 to 3.5 percent swell. Samples tested in the laboratory contained 5 to 59 percent clay and silt-sized particles (passing the No. 200 sieve). Atterberg limit testing indicated liquid limits of 25 to 32 and plasticity indices of 10 to 19. Two samples were non-plastic. Hveem Stabilometer tests of two bulk samples indicated R-values of 26 and 28. Groundwater was encountered in one boring at approximately 8 feet. Groundwater fluctuates seasonally and will be affected by irrigation and precipitation. Groundwater is not expected to affect pavement construction for the included roads. Further description of the subsurface conditions is presented in our boring logs and laboratory test results. Pavement Design New construction is planned for the subject roadways. We understand roadway improvements are regulated by the Larimer County Urban Area Street Standards August 2021 (LCUASS), which requires the use of the AASHTO pavement design methods for their HARTFORD HOMES BLOOM FILING 1 ROADS - PHASE 3 CTL  T PROJECT NO. FC07733.010-135 4 roadways. These design methods require input parameters for traffic projections for a specified design life, roadway classification, characteristics of the subgrade materials, type and strength characteristics of pavement materials, groundwater conditions, drainage conditions, and statistical data. Traffic Projections Traffic projections are typically expressed as an 18-kip Equivalent Daily Load Application (EDLA) for a single day or as an 18-kip Equivalent Single Axle Load (ESAL) for the design period of 20 years. Traffic projections were not provided to us for this report. We used Table 10.1: Flexible Pavement Design Criteria from LCUASS for assumed ESAL loads. Table A presents the roadway classifications and Design ESALs used with our calculations. Table A: Design 18-kip Equivalent Single Axle Loads (ESALs) Street Flexible ESAL Rigid ESAL Donella Drive, Aria Way (Sykes to Donella Drive), and Delozier Road (Sykes to Donella Drive) (Minor Collector) 182,500 239,000 International Boulevard (Two-Lane Arterial) 730,000 957,000 Subgrade and Groundwater Conditions The subgrade soils generally consist of clean to clayey, gravelly sand or sandy clay that classifies as A-4 to A-6 in accordance with AASHTO classification methods. Hveem stabilometer tests of composite samples of the sandy clay and clayey sand resulted in R-values of 26 to 28. We used the R-value of 26 which we converted to a resilient modulus of 8,432 psi based on CDOT criteria. Moderately to highly plastic clay and higher swelling soils were encountered during this investigation. Mitigation for expansive soil is required by LCUASS if swell potential is 2.0 percent or greater. Mitigation can consist of moisture treatment and re- compaction or chemical treatment of 12 inches of the subgrade below the included roadways. We understand that cement treatment has been a preferred stabilization method used at this site. This is discussed in Subgrade and Pavement Materials and Construction. Groundwater was encountered at a depth of approximately 8 feet in one boring during this investigation. Groundwater is not expected to interfere with the performance of the pavement. HARTFORD HOMES BLOOM FILING 1 ROADS - PHASE 3 CTL  T PROJECT NO. FC07733.010-135 5 Pavement Thickness Calculations We used AASHTO methods to develop our pavement thickness calculations for flexible and rigid pavements with input values provided by the LCUASS, our laboratory tests, and observations. Input values including initial and terminal serviceability indices, reliability factor, and layer strength coefficients were taken from LCUASS. Other input values not specified by the LCUASS were estimated based on our experience with similar projects. Computer- generated printouts of the pavement calculations are presented in Appendix B. Pavement Recommendations For our design, we assume the pavement will be constructed during a single stage. If multiple-stage construction is desired, we should be consulted to revise our recommendations. We have provided pavement design recommendations for new construction including hot mix asphalt (HMA) on aggregate base course (ABC), and Portland cement concrete (PCC). Cement treatment of the upper 12 inches of subgrade can be used to mitigate swelling soils and soft soils. Moisture treatment and re-compaction of 12 inches of subgrade is also acceptable for mitigating swelling soils. Minimum pavement thickness recommendations are presented on Table B. TABLE B: MINIMUM PAVEMENT THICKNESS RECOMMENDATIONS Roadway Hot Mix Asphalt (HMA) + Aggregate Base Course (ABC) + Chemical Treated Subgrade (CTS) or Moisture Treated Subgrade (MTS) Portland Cement Concrete (PCC) + Chemical Treated Subgrade (CTS) or Moisture Treated Subgrade (MTS) Donella Drive, Aria Way (Sykes to Donella Drive), and Delozier Road (Sykes to Donella Drive) (Minor Collector) 5.5” HMA + 7” ABC + 12” CTS/MTS 6” PCC + 12” CTS/MTS International Boulevard (Two-Lane Arterial) 7.5” HMA + 11.5” ABC + 12” CTS/MTS 8” PCC + 12” CTS/MTS HARTFORD HOMES BLOOM FILING 1 ROADS - PHASE 3 CTL  T PROJECT NO. FC07733.010-135 6 Subgrade and Pavement Materials and Construction The construction materials are assumed to possess sufficient quality as reflected by the strength factors used in our design calculations. Materials and construction requirements of LCUASS 2021 or CDOT should be followed. LUCASS requires mitigation of swelling soils when swell potential is 2.0 percent or greater. Based on the results of laboratory testing, our experience, and LCUASS, we believe that mitigation for swell will be required below the included roadways. Soft saturated soils have been encountered throughout the site because of higher-than-normal precipitation. Cement treatment has been used as the preferred stabilization method for the site roadways to address both problems. Cement reduces the plasticity and swell potential of soil and also increases its bearing capacity. Cement concentration for subgrade stabilization typically ranges between 4 to 7 percent by weight. We believe 4 to 5 percent will likely be necessary at this site. We recommend a minimum of 1-day curing period (3 days is preferred) prior to paving for cement treatment. The surface of the stabilized area should be kept moist during the cure period by periodic, light sprinkling if needed. Strength gains will be slower during cooler weather. Traffic should not be permitted on the treated subgrade during the curing period. Mixing of the treated subgrade should not occur if the temperature of the soil mixture is below 40 degrees Fahrenheit. The subgrade should be protected from freezing or drying at all times until paving. We do not recommend placing asphalt pavement directly on cement treated subgrade. Placement, mixing, and compaction of stabilized subgrade should be observed and tested by our firm. Recommendations for paving materials and subgrade preparations, including moisture and chemical treatment, are presented in Appendix C. Preparation of the subgrade should extend from back-of-walk to back-of-walk for attached or monolithic walks or back-of-curb to back-of-curb. These criteria were developed from analysis of the field and laboratory data, our experience, LCUASS, and CDOT requirements. If the materials cannot meet these requirements, our pavement recommendations should be re-evaluated based upon available materials. The use of recycled materials, such as recycled asphalt pavement (RAP) and recycled concrete may be used in place of aggregate base course (ABC) provided they meet minimum R-values and gradations established by LCUASS. Materials planned for construction should be submitted and the applicable laboratory tests performed to verify compliance with the specifications. HARTFORD HOMES BLOOM FILING 1 ROADS - PHASE 3 CTL  T PROJECT NO. FC07733.010-135 7 Water-Soluble Sulfates The method of applying the stabilizing agent to the soil will depend partly on the level of water-soluble sulfates in the subgrade soil. A reaction of water-soluble sulfates in the soil and available calcium in the stabilizing agent can occur creating the mineral ettringite, which can swell causing detrimental effects to the pavement surface. When unacceptable concentrations of water-soluble sulfates are present in the soil, the double-application method can reduce the risk of pavement heave due to ettringite formation to an acceptable level. We measured water- soluble sulfate concentrations in nine samples for this investigation and thirty-six samples from previous investigations. Seven samples were between 0.20 and 2.00 percent and three were between 0.10 to 0.20 percent with all other samples being below measurable to 0.09 percent. Our threshold limit of water-soluble sulfates in soils for single application of cement, fly ash, or lime for stabilization is 0.5 percent. At levels greater than 0.5 percent, special application processes are necessary. Based on our test results, we believe single application is appropriate below most of the included roads. However, concentration was high in one of the borings on Donella Drive indicating a severe exposure class. A double application is recommended if cement treatment is selected for the west side of Donella Drive. Our testing does not delineate the area that the high level extends to include. Other areas of high sulfate levels may exist. Additional testing may be warranted prior to using chemical treatment for the subgrade in the area of boring TH-7. A conservative approach would be to extend the area of double application farther away from the identified boring and include nearby areas. In addition to the interaction of water-soluble sulfates with chemical treatment agents, concrete that is exposed to sulfate-rich soils can be subject to sulfate attack. If concrete pavements or structures will not be in contact with sulfate-rich soils, by means of an aggregate base course layer or other materials, the risk of sulfate attack should be low. Based on our cumulative test results, our experience, and ACI 332-20, the sulfate exposure class is RS2 (see Table C). Deviations from the exposure class may occur as a result of additional sampling and testing. TABLE C: SULFATE EXPOSURE CLASSES PER ACI 332-20 Exposure Classes Water-Soluble Sulfate (SO4) in Soil A (%) Not Applicable RS0 < 0.10 Moderate RS1 0.10 to 0.20 Severe RS2 0.20 to 2.00 Very Severe RS3 > 2.00 A) Percent sulfate by mass in soil determined by ASTM C1580 HARTFORD HOMES BLOOM FILING 1 ROADS - PHASE 3 CTL  T PROJECT NO. FC07733.010-135 8 For this level of sulfate concentration, ACI 332-20 indicates there are special cement type requirements for sulfate resistance as indicated in Table D. TABLE D: CONCRETE DESIGN REQUIREMENTS FOR SULFATE EXPOSURE PER ACI 332-20 Exposure Class Maximum Water/ Cement Ratio Minimum Compressive Strength A (psi) Cementitious Material Types B Calcium Chloride Admixtures ASTM C150/ C150M ASTM C595/ C595M ASTM C1157/ C1157M RS0 N/A 2500 No Type Restrictions No Type Restrictions No Type Restrictions No Restrictions RS1 0.50 2500 II Type with (MS) Designation MS No Restrictions RS2 0.45 3000 V C Type with (HS) Designation HS Not Permitted RS3 0.45 3000 V + Pozzolan or Slag Cement D Type with (HS) Designation plus Pozzolan or Slag Cement E HS + Pozzolan or Slag Cement E Not Permitted A) Concrete compressive strength specified shall be based on 28-day tests per ASTM C39/C39M B) Alternate combinations of cementitious materials of those listed in ACI 332-20 Table 5.4.2 shall be permitted when tested for sulfate resistance meeting the criteria in section 5.5. C) Other available types of cement such as Type III or Type I are permitted in Exposure Classes RS1 or RS2 if the C3A contents are less than 8 or 5 percent, respectively. D) The amount of the specific source of pozzolan or slag to be used shall not be less than the amount that has been determined by service record to improve sulfate resistance when used in concrete containing Type V cement. Alternatively, the amount of the specific source of the pozzolan or slab to be used shall not be less than the amount tested in accordance with ASTM C1012/C1012M and meeting the criteria in section 5.5.1 of ACI 332-20. E) Water-soluble chloride ion content that is contributed from the ingredients including water aggregates, cementitious materials, and admixtures shall be determined on the concrete mixture ASTM C1218/C1218M between 29 and 42 days. Superficial damage may occur to the exposed surfaces of highly permeable concrete, even though sulfate levels are relatively low. To control this risk and to resist freeze-thaw deterioration, the water-to-cementitious materials ratio should not exceed 0.50 for concrete in contact with soils that are likely to stay moist due to surface drainage or high-water tables. Concrete should have a total air content of 6 percent ± 1.5 percent. Maintenance Routine maintenance, such as sealing and repair of cracks, is necessary to achieve the long-term life of a pavement system. We recommend a preventive maintenance program be developed and followed for all pavement systems to ensure that design life can be realized. Choosing to defer maintenance usually results in accelerated deterioration leading to higher future maintenance costs and/or repair. A recommended maintenance program is outlined in Appendix D. HARTFORD HOMES BLOOM FILING 1 ROADS - PHASE 3 CTL  T PROJECT NO. FC07733.010-135 9 Excavation of completed pavement for utility construction or repair can destroy the integrity of the pavement and result in a severe decrease in serviceability. To restore the pavement top original serviceability, careful backfill compaction before repaving is necessary. Surface Drainage A primary cause of premature pavement deterioration is infiltration of water into the pavement system. This increase in moisture content usually results in the softening of base course and subgrade soil and eventual failure of the pavement. In addition, parts of Colorado experience many freeze-thaw cycles each season that can result in deterioration of the pavement. We recommend that subgrade, pavement, and surrounding ground surface be sloped to cause surface water to run off rapidly and away from pavements. Backs of curbs and gutters should be backfilled with compacted fill and sloped to prevent ponding adjacent to backs of curbs and to paving. The final grading of the subgrade should be carefully controlled so the pavement design cross-section can be maintained. Low spots in the subgrade that can trap water should be eliminated. Seals should be provided within the curb and pavement, and in all joints to reduce the possibility of water infiltration. Limitations This report has been prepared for the exclusive use of Hartford Homes for the purpose of providing geotechnical design and construction criteria for the proposed project. This report was prepared from data developed during our field exploration, laboratory testing, engineering analysis, and experience with similar conditions. The borings were spaced to obtain a reasonably accurate understanding of the existing pavements and subsurface conditions. The borings are representative of conditions encountered only at the exact boring locations. Variations in subsurface conditions not indicated by our borings are always possible. The recommendations contained in this report were based upon our understanding of the planned construction. If plans change or differ from the assumptions presented herein, we should be contacted to review our recommendations. A representative of our firm should observe subgrade preparation and pavement construction. Our representative should also conduct tests of construction materials for compliance with recommendations presented in this report and/or specifications of the controlling agency. HARTFORD HOMES BLOOM FILING 1 ROADS - PHASE 3 CTL  T PROJECT NO. FC07733.010-135 10 Due to the changing nature of site characterization, pavement design methods, standards, and practices, the information and recommendations provided in this report are only valid for one year following the date of issue. Following that time, our office should be contacted to provide, if necessary, any updated recommendations and design criteria as appropriate for the engineering methodologies used at that time. We believe this investigation was conducted in a manner consistent with that level of skill and care ordinarily used by members of the profession currently practicing under similar conditions in the locality of this project. No warranty, express or implied, is made. If we can be of further service in discussing the contents of this report or in the analysis of the influence of subsurface conditions on design of the pavements, please call. CTL | THOMPSON, INC. Trace Krausse, PE R.B. “Chip” Leadbetter, III, PE Geotechnical Project Manager Senior Engineer TH-1 TH-2 TH-3 TH-4 TH-7 TH-8 TH-6 TH-5 Ari a W ay International Boulevard Gre e n f i e l d s D ri v e Donella Drive Del o z i e r R oa d Crusader Street TI M B E R L I N E R D . I- 2 5 E. MULBERRY ST. E. VINE DR. SITE LEGEND: INDICATES APPROXIMATE LOCATION OF EXPLORATORY BORING TH-1 HARTFORD HOMES BLOOM FILING 1 ROADS PHASE 3 CTL I T PROJECT NO. FC07733.010-135 FIGURE 1 Locations of Exploratory Borings VICINITY MAP (FORT COLLINS, COLORADO) NOT TO SCALE 450'225' APPROXIMATE SCALE: 1" = 450' 0' 0 5 10 15 20 25 30 35 40 0 5 10 15 20 25 30 35 40 26/12 25/12 13/12 WC=12.7DD=118SW=2.9SS=<0.01 WC=6.2LL=25 PI=10-200=41 TH-1 23/12 13/12 32/12 WC=9.5DD=126LL=31 PI=18-200=50 WC=7.2DD=108SW=1.0SS=0.070 TH-2 22/12 29/12 15/12 WC=7.0DD=123SW=3.5SS=<0.01 WC=0.9LL=NV PI=NP-200=5 TH-3 23/12 21/12 18/12 WC=6.6DD=117SW=3.2SS=0.090 WC=1.6LL=NV PI=NP-200=9 TH-4 DRIVE SAMPLE. THE SYMBOL 26/12 INDICATES 26 BLOWS OF A 140-POUND HAMMER FALLING 30 INCHES WERE REQUIRED TO DRIVE A 2.5-INCH O.D. SAMPLER 12 INCHES. CLAY, SANDY, SLIGHTLY MOIST TO MOIST, STIFF TO VERY STIFF, BROWN 1. 3. LEGEND: SAND, GRAVELLY, CLEAN TO SLIGHTLY CLAYEY, SLIGHTLY MOIST TO MOIST, MEDIUM DENSE TO DENSE, RED-BROWN, GREY (SP, SP-SC) GRAVEL, SANDY, CLEAN TO SLIGHTLY CLAYEY, MOIST TO WET, MEDIUM DENSE, RED- BROWN, GREY (GP) CLAY, SANDY WITH OCCASIONAL GRAVEL, MOIST, STIFF TO VERY STIFF, RED, BROWN (CL) DE P T H - F E E T THESE LOGS ARE SUBJECT TO THE EXPLANATIONS, LIMITATIONS AND CONCLUSIONS IN THIS REPORT. NOTES: FILL, SAND, CLAYEY, GRAVELLY, SLIGHTLY MOIST TO MOIST, LOOSE TO MEDIUM DENSE, BROWN INDICATES MOISTURE CONTENT (%). INDICATES DRY DENSITY (PCF). INDICATES SWELL WHEN WETTED UNDER OVERBURDEN PRESSURE (%). INDICATES PASSING NO. 200 SIEVE (%). INDICATES LIQUID LIMIT. INDICATES PLASTICITY INDEX. INDICATES SOLUBLE SULFATE CONTENT (%). 2. DE P T H - F E E T WATER LEVEL MEASURED AFTER DRILLING. Summary Logs of Exploratory Borings THE BORINGS WERE DRILLED ON OCTOBER 4TH, 2023 USING 4-INCH DIAMETER CONTINUOUS-FLIGHT AUGERS AND A TRUCK-MOUNTED DRILL RIG. FIGURE 2 WC DD SW -200 LL PI SS - - - - - - - HARTFORD HOMES BLOOM FILING 1 ROADS PHASE 3 CTL | T PROJECT NO. FC07733.010-135 0 5 10 15 20 25 30 35 40 0 5 10 15 20 25 30 35 40 24/12 23/12 32/12 WC=7.7DD=128SW=1.2SS=<0.01 WC=10.7LL=32 PI=19-200=49 TH-5 20/12 14/12 41/12 WC=14.9DD=119LL=32 PI=18-200=59 WC=10.5DD=121SW=0.4SS=<0.01 TH-6 10/12 10/12 13/12 WC=11.3DD=118SW=1.1SS=0.750 WC=10.9LL=29 PI=15-200=46 SS=0.800 TH-7 21/12 13/12 50/12 WC=11.1DD=121LL=28 PI=15-200=57 WC=17.3DD=114SW=-1.1SS=0.070 TH-8 Summary Logs of Exploratory Borings FIGURE 3 DE P T H - F E E T DE P T H - F E E T HARTFORD HOMES BLOOM FILING 1 ROADS PHASE 3 CTL | T PROJECT NO. FC07733.010-135 APPENDIX A RESULTS OF LABORATORY TESTS TABLE A-I – SUMMARY OF LABORATORY TESTING Sample of FILL, CLAY, SANDY (CL) DRY UNIT WEIGHT=118 PCF From TH - 1 AT 2 FEET MOISTURE CONTENT=12.7 % Sample of FILL, CLAY, SANDY (CL) DRY UNIT WEIGHT=108 PCF From TH - 2 AT 4 FEET MOISTURE CONTENT=7.2 % HARTFORD HOMES BLOOM FILING 1 ROADS PHASE 3 CTL | T PROJECT NO. FC07733.010-135 APPLIED PRESSURE - KSF CO M P R E S S I O N % E X P A N S I O N Swell Consolidation FIGURE A-1 CO M P R E S S I O N % E X P A N S I O N -3 -2 -1 0 1 2 3 4 EXPANSION UNDER CONSTANT PRESSURE DUE TO WETTING 0.1 10 1001.0 0.1 1.0 10 100APPLIED PRESSURE - KSF -4 -3 -2 -1 0 1 2 3 EXPANSION UNDER CONSTANT PRESSURE DUE TO WETTING Sample of FILL, CLAY, SANDY (CL) DRY UNIT WEIGHT=123 PCF From TH - 3 AT 2 FEET MOISTURE CONTENT=7.0 % HARTFORD HOMES BLOOM FILING 1 ROADS PHASE 3 CTL | T PROJECT NO. FC07733.010-135 APPLIED PRESSURE - KSF CO M P R E S S I O N % E X P A N S I O N Swell Consolidation Test Results FIGURE A-2 -8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 EXPANSION UNDER CONSTANT PRESSURE DUE TO WETTING 0.1 1.0 10 100 Sample of FILL, CLAY, SANDY (CL) DRY UNIT WEIGHT=117 PCF From TH - 4 AT 2 FEET MOISTURE CONTENT=6.6 % HARTFORD HOMES BLOOM FILING 1 ROADS PHASE 3 CTL | T PROJECT NO. FC07733.010-135 APPLIED PRESSURE - KSF CO M P R E S S I O N % E X P A N S I O N Swell Consolidation Test Results FIGURE A-3 -8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 EXPANSION UNDER CONSTANT PRESSURE DUE TO WETTING 0.1 1.0 10 100 Sample of FILL, CLAY, SANDY (CL) DRY UNIT WEIGHT=128 PCF From TH - 5 AT 2 FEET MOISTURE CONTENT=7.7 % Sample of FILL, CLAY, SANDY (CL) DRY UNIT WEIGHT=121 PCF From TH - 6 AT 4 FEET MOISTURE CONTENT=10.5 % HARTFORD HOMES BLOOM FILING 1 ROADS PHASE 3 CTL | T PROJECT NO. FC07733.010-135 APPLIED PRESSURE - KSF CO M P R E S S I O N % E X P A N S I O N Swell Consolidation FIGURE A-4 CO M P R E S S I O N % E X P A N S I O N -4 -3 -2 -1 0 1 2 3 EXPANSION UNDER CONSTANT PRESSURE DUE TO WETTING 0.1 10 1001.0 0.1 1.0 10 100APPLIED PRESSURE - KSF -4 -3 -2 -1 0 1 2 3 EXPANSION UNDER CONSTANT PRESSURE DUE TO WETTING Sample of FILL, CLAY, SANDY (CL) DRY UNIT WEIGHT=118 PCF From TH - 7 AT 2 FEET MOISTURE CONTENT=11.3 % Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=114 PCF From TH - 8 AT 4 FEET MOISTURE CONTENT=17.3 % HARTFORD HOMES BLOOM FILING 1 ROADS PHASE 3 CTL | T PROJECT NO. FC07733.010-135 APPLIED PRESSURE - KSF CO M P R E S S I O N % E X P A N S I O N Swell Consolidation FIGURE A-5 CO M P R E S S I O N % E X P A N S I O N -4 -3 -2 -1 0 1 2 3 EXPANSION UNDER CONSTANT PRESSURE DUE TO WETTING 0.1 10 1001.0 0.1 1.0 10 100APPLIED PRESSURE - KSF -4 -3 -2 -1 0 1 2 3 ADDITIONAL COMPRESSION UNDER CONSTANT PRESSURE DUE TO WETTING Sample of FILL, SAND, CLAYEY (SC)GRAVEL 5 %SAND 49 % From S - 1 AT 0-4 FEET SILT & CLAY 46 %LIQUID LIMIT 29 % PLASTICITY INDEX 16 % Sample of FILL, CLAY, SANDY (CL)GRAVEL 4 %SAND 43 % From S - 2 AT 0-4 FEET SILT & CLAY 53 %LIQUID LIMIT 32 % PLASTICITY INDEX 19 % HARTFORD HOMES BLOOM FILING 1 ROADS PHASE 3 CTL | T PROJECT NO. FC07733.010-135 FIGURE A-6 Gradation Test Results 0.002 15 MIN. .005 60 MIN. .009 19 MIN. .019 4 MIN. .037 1 MIN. .074 *200 .149 *100 .297 *50 0.42 *40 .590 *30 1.19 *16 2.0 *10 2.38 *8 4.76 *4 9.52 3/8" 19.1 3/4" 36.1 1½" 76.2 3" 127 5" 152 6" 200 8" .001 45 MIN. 0 10 20 30 40 50 60 70 80 90 100 CLAY (PLASTIC) TO SILT (NON-PLASTIC)SANDS FINE MEDIUM COARSE GRAVEL FINE COARSE COBBLES DIAMETER OF PARTICLE IN MILLIMETERS 25 HR.7 HR. HYDROMETER ANALYSIS SIEVE ANALYSIS TIME READINGS U.S. STANDARD SERIES CLEAR SQUARE OPENINGS PE R C E N T P A S S I N G 0 10 20 30 50 60 70 80 90 100 PE R C E N T R E T A I N E D 40 0.002 15 MIN. .005 60 MIN. .009 19 MIN. .019 4 MIN. .037 1 MIN. .074 *200 .149 *100 .297 *50 0.42 *40 .590 *30 1.19 *16 2.0 *10 2.38 *8 4.76 *4 9.52 3/8" 19.1 3/4" 36.1 1½" 76.2 3" 127 5" 152 6" 200 8" .001 45 MIN. 0 10 20 30 40 50 60 70 80 90 100 CLAY (PLASTIC) TO SILT (NON-PLASTIC)SANDS FINE MEDIUM COARSE GRAVEL FINE COARSE COBBLES DIAMETER OF PARTICLE IN MILLIMETERS 25 HR.7 HR. HYDROMETER ANALYSIS SIEVE ANALYSIS TIME READINGS U.S. STANDARD SERIES CLEAR SQUARE OPENINGS PE R C E N T P A S S I N G PE R C E N T R E T A I N E D 0 10 20 30 40 50 60 70 80 90 100 Sample of SAND, GRAVELLY (SP)GRAVEL 21 %SAND 74 % From TH - 3 AT 4 FEET SILT & CLAY 5 %LIQUID LIMIT NV % PLASTICITY INDEX NP % Sample of SAND, GRAVELLY (SP)GRAVEL 21 %SAND 70 % From TH - 4 AT 4 FEET SILT & CLAY 9 %LIQUID LIMIT NV % PLASTICITY INDEX NP % HARTFORD HOMES BLOOM FILING 1 ROADS PHASE 3 CTL | T PROJECT NO. FC07733.010-135 FIGURE A-7 Gradation Test Results 0.002 15 MIN. .005 60 MIN. .009 19 MIN. .019 4 MIN. .037 1 MIN. .074 *200 .149 *100 .297 *50 0.42 *40 .590 *30 1.19 *16 2.0 *10 2.38 *8 4.76 *4 9.52 3/8" 19.1 3/4" 36.1 1½" 76.2 3" 127 5" 152 6" 200 8" .001 45 MIN. 0 10 20 30 40 50 60 70 80 90 100 CLAY (PLASTIC) TO SILT (NON-PLASTIC)SANDS FINE MEDIUM COARSE GRAVEL FINE COARSE COBBLES DIAMETER OF PARTICLE IN MILLIMETERS 25 HR.7 HR. HYDROMETER ANALYSIS SIEVE ANALYSIS TIME READINGS U.S. STANDARD SERIES CLEAR SQUARE OPENINGS PE R C E N T P A S S I N G 0 10 20 30 50 60 70 80 90 100 PE R C E N T R E T A I N E D 40 0.002 15 MIN. .005 60 MIN. .009 19 MIN. .019 4 MIN. .037 1 MIN. .074 *200 .149 *100 .297 *50 0.42 *40 .590 *30 1.19 *16 2.0 *10 2.38 *8 4.76 *4 9.52 3/8" 19.1 3/4" 36.1 1½" 76.2 3" 127 5" 152 6" 200 8" .001 45 MIN. 0 10 20 30 40 50 60 70 80 90 100 CLAY (PLASTIC) TO SILT (NON-PLASTIC)SANDS FINE MEDIUM COARSE GRAVEL FINE COARSE COBBLES DIAMETER OF PARTICLE IN MILLIMETERS 25 HR.7 HR. HYDROMETER ANALYSIS SIEVE ANALYSIS TIME READINGS U.S. STANDARD SERIES CLEAR SQUARE OPENINGS PE R C E N T P A S S I N G PE R C E N T R E T A I N E D 0 10 20 30 40 50 60 70 80 90 100 Sample of FILL, CLAY, SANDY (CL)GRAVEL 4 %SAND 47 % From TH - 5 AT 4 FEET SILT & CLAY 49 %LIQUID LIMIT 32 % PLASTICITY INDEX 19 % Sample of FILL, CLAY, SANDY (CL)GRAVEL 2 %SAND 39 % From TH - 6 AT 2 FEET SILT & CLAY 59 %LIQUID LIMIT 32 % PLASTICITY INDEX 18 % HARTFORD HOMES BLOOM FILING 1 ROADS PHASE 3 CTL | T PROJECT NO. FC07733.010-135 FIGURE A-8 Gradation Test Results 0.002 15 MIN. .005 60 MIN. .009 19 MIN. .019 4 MIN. .037 1 MIN. .074 *200 .149 *100 .297 *50 0.42 *40 .590 *30 1.19 *16 2.0 *10 2.38 *8 4.76 *4 9.52 3/8" 19.1 3/4" 36.1 1½" 76.2 3" 127 5" 152 6" 200 8" .001 45 MIN. 0 10 20 30 40 50 60 70 80 90 100 CLAY (PLASTIC) TO SILT (NON-PLASTIC)SANDS FINE MEDIUM COARSE GRAVEL FINE COARSE COBBLES DIAMETER OF PARTICLE IN MILLIMETERS 25 HR.7 HR. HYDROMETER ANALYSIS SIEVE ANALYSIS TIME READINGS U.S. STANDARD SERIES CLEAR SQUARE OPENINGS PE R C E N T P A S S I N G 0 10 20 30 50 60 70 80 90 100 PE R C E N T R E T A I N E D 40 0.002 15 MIN. .005 60 MIN. .009 19 MIN. .019 4 MIN. .037 1 MIN. .074 *200 .149 *100 .297 *50 0.42 *40 .590 *30 1.19 *16 2.0 *10 2.38 *8 4.76 *4 9.52 3/8" 19.1 3/4" 36.1 1½" 76.2 3" 127 5" 152 6" 200 8" .001 45 MIN. 0 10 20 30 40 50 60 70 80 90 100 CLAY (PLASTIC) TO SILT (NON-PLASTIC)SANDS FINE MEDIUM COARSE GRAVEL FINE COARSE COBBLES DIAMETER OF PARTICLE IN MILLIMETERS 25 HR.7 HR. HYDROMETER ANALYSIS SIEVE ANALYSIS TIME READINGS U.S. STANDARD SERIES CLEAR SQUARE OPENINGS PE R C E N T P A S S I N G PE R C E N T R E T A I N E D 0 10 20 30 40 50 60 70 80 90 100 Sample of FILL, CLAY, SANDY (CL)GRAVEL 9 %SAND 45 % From TH - 7 AT 4 FEET SILT & CLAY 46 %LIQUID LIMIT 29 % PLASTICITY INDEX 15 % Sample of CLAY, SANDY (CL)GRAVEL 3 %SAND 40 % From TH - 8 AT 2 FEET SILT & CLAY 57 %LIQUID LIMIT 28 % PLASTICITY INDEX 15 % HARTFORD HOMES BLOOM FILING 1 ROADS PHASE 3 CTL | T PROJECT NO. FC07733.010-135 FIGURE A-9 Gradation Test Results 0.002 15 MIN. .005 60 MIN. .009 19 MIN. .019 4 MIN. .037 1 MIN. .074 *200 .149 *100 .297 *50 0.42 *40 .590 *30 1.19 *16 2.0 *10 2.38 *8 4.76 *4 9.52 3/8" 19.1 3/4" 36.1 1½" 76.2 3" 127 5" 152 6" 200 8" .001 45 MIN. 0 10 20 30 40 50 60 70 80 90 100 CLAY (PLASTIC) TO SILT (NON-PLASTIC)SANDS FINE MEDIUM COARSE GRAVEL FINE COARSE COBBLES DIAMETER OF PARTICLE IN MILLIMETERS 25 HR.7 HR. HYDROMETER ANALYSIS SIEVE ANALYSIS TIME READINGS U.S. STANDARD SERIES CLEAR SQUARE OPENINGS PE R C E N T P A S S I N G 0 10 20 30 50 60 70 80 90 100 PE R C E N T R E T A I N E D 40 0.002 15 MIN. .005 60 MIN. .009 19 MIN. .019 4 MIN. .037 1 MIN. .074 *200 .149 *100 .297 *50 0.42 *40 .590 *30 1.19 *16 2.0 *10 2.38 *8 4.76 *4 9.52 3/8" 19.1 3/4" 36.1 1½" 76.2 3" 127 5" 152 6" 200 8" .001 45 MIN. 0 10 20 30 40 50 60 70 80 90 100 CLAY (PLASTIC) TO SILT (NON-PLASTIC)SANDS FINE MEDIUM COARSE GRAVEL FINE COARSE COBBLES DIAMETER OF PARTICLE IN MILLIMETERS 25 HR.7 HR. HYDROMETER ANALYSIS SIEVE ANALYSIS TIME READINGS U.S. STANDARD SERIES CLEAR SQUARE OPENINGS PE R C E N T P A S S I N G PE R C E N T R E T A I N E D 0 10 20 30 40 50 60 70 80 90 100 PASSING WATER- MOISTURE DRY LIQUID PLASTICITY APPLIED NO. 200 SOLUBLE DEPTH CONTENT DENSITY LIMIT INDEX SWELL*PRESSURE SIEVE SULFATES BORING (FEET)(%)(PCF)(%)(PSF)(%)(%)DESCRIPTION S-1 0-4 7.6 29 16 46 FILL, SAND, CLAYEY (SC) S-2 0-4 8.7 32 19 53 FILL, CLAY, SANDY (CL) TH-1 2 12.7 118 2.9 150 <0.01 FILL, CLAY, SANDY (CL) TH-1 4 6.2 25 10 41 FILL, SAND, CLAYEY (SC) TH-2 2 9.5 126 31 18 50 FILL, CLAY, SANDY (CL) TH-2 4 7.2 108 1.0 150 0.07 FILL, CLAY, SANDY (CL) TH-3 2 7.0 123 3.5 150 <0.01 FILL, CLAY, SANDY (CL) TH-3 4 0.9 NV NP 5 SAND (SP) TH-4 2 6.6 117 3.2 150 0.09 FILL, CLAY, SANDY (CL) TH-4 4 1.6 NV NP 9 SAND, GRAVELLY (SP-SC) TH-5 2 7.7 128 1.2 150 <0.01 FILL, CLAY, SANDY (CL) TH-5 4 10.7 32 19 49 FILL, SAND, CLAYEY (SC) TH-6 2 14.9 119 32 18 59 FILL, CLAY, SANDY (CL) TH-6 4 10.5 121 0.4 150 <0.01 FILL, CLAY, SANDY (CL) TH-7 2 11.3 118 1.1 150 0.75 FILL, CLAY, SANDY (CL) TH-7 4 10.9 29 15 46 FILL, SAND, CLAYEY (SC) TH-7 9 0.80 FILL, CLAY, SANDY (CL) TH-8 2 11.1 121 28 15 57 CLAY, SANDY (CL) TH-8 4 17.3 114 -1.1 150 0.07 CLAY, SANDY (CL) SWELL TEST RESULTS* TABLE A-I SUMMARY OF LABORATORY TESTING ATTERBERG LIMITS Page 1 of 1 * NEGATIVE VALUE INDICATES COMPRESSION. HARTFORD HOMES BLOOM FILING 1 ROADS PHASE 3 CTL|T PROJECT NO. FC07733.010-135 Specification Title:Onsite/Native (Clay or Silt) ASTM D75 / AASHTO T2 / CDOT CP30 Material Description: Sample Location: Light brown, CLAY Soil Sampling: CTL FCO7733.101, S-1 R-Value (ASTM D2844) 35 26 18 0100200300400500600700 Exudation Pressure (psi) 0 20 40 60 80 100 R - V a l u e Test Point Moisture (%) Exudation Pressure (psi) R-Value 1 12.8 303 26 2 14.1 145 18 3 10.5 494 35 R- Value at 300 psi Exudation Pressure 26 Remarks: 10.5 12.8 14.1 0100200300400500600700 Exudation Pressure (psi) 0 10 20 30 40 50 M o i s t u r e C o n t e n t ( % ) Sampling Method: CTL Thompson 400 North Link Lane Fort Collins, CO 80524 Craig Ellis CTL Thompson - 2021-2022 Misc Lab Testing Client: Report Date: Soil/Aggregate Laboratory Summary 21-0609.SoilSampling.0042; ver: 2Oct 19, 2023 Work Order No.: Work Order Date:Oct 6, 2023 Reviewed by:Drew Servold Results apply only to the specific items and locations referenced and at the time of testing, observations or special inspections. Unless noted otherwise, samples were received in adequate condition. This report should not be reproduced, except in full, without the written permission of GROUND Engineering Consultants, Inc. 41 Inverness Drive East, Englewood, Colorado www.groundeng.com 303-289-1989 Englewood | Commerce City | Loveland | Granby | Gypsum | Colorado Springs HARTFORD HOMES BLOOM FILING 1 ROADS PHASE 3 CTL|T PROJECT NO. FC07733.010-135 Specification Title:Onsite/Native (Clay or Silt) ASTM D75 / AASHTO T2 / CDOT CP30 Material Description: Sample Location: Light brown, CLAY Soil Sampling: CTL FC07733.010, S-2 R-Value (ASTM D2844) 38 28 19 0100200300400500600700 Exudation Pressure (psi) 0 20 40 60 80 100 R - V a l u e Test Point Moisture (%) Exudation Pressure (psi) R-Value 1 13.3 302 28 2 15.1 177 19 3 11.4 474 38 R- Value at 300 psi Exudation Pressure 28 Remarks: 11.4 13.3 15.1 0100200300400500600700 Exudation Pressure (psi) 0 10 20 30 40 50 M o i s t u r e C o n t e n t ( % ) Sampling Method: CTL Thompson - 2021-2022 Misc Lab TestingReport Date: Soil/Aggregate Laboratory Summary 21-0609.SoilSampling.0040; ver: 2Oct 19, 2023 Work Order No.: Work Order Date:Oct 6, 2023 Reviewed by:Drew Servold Results apply only to the specific items and locations referenced and at the time of testing, observations or special inspections. Unless noted otherwise, samples were received in adequate condition. This report should not be reproduced, except in full, without the written permission of GROUND Engineering Consultants, Inc. 41 Inverness Drive East, Englewood, Colorado www.groundeng.com 303-289-1989 Englewood | Commerce City | Loveland | Granby | Gypsum | Colorado Springs HARTFORD HOMES BLOOM FILING 1 ROADS PHASE 3 CTL|T PROJECT NO. FC07733.010-135 APPENDIX B AASHTO FLEXIBLE PAVEMENT DESIGN CALCULATIONS Roadway(s): Reliability 75 % Standard Deviation 0.44 Initial Serviceability 4.5 Terminal Serviceability 2.3 Resilient Modulus 8,432 psi Design ESALs 182,500 Layers Structural Coefficient Drainage Thickness SN HMA 0.44 1 5.5 2.42 ABC 0.11 1.05 7 0.81 CSS 0.1 1 0 0.00 SUM 3.23 HARTFORD HOMES BLOOM FILING 1 ROADS, PHASE 3 CTL|T PROJECT NO. FC07733.010-135 Design Structural Number 2.22 Aria Way and Delozier Road (Sykes to Donella Dr.) and Donella Drive Minor Collector Flexible Structural Design FIGURE B-1 Roadway(s): Reliability 90 % Standard Deviation 0.44 Initial Serviceability 4.5 Terminal Serviceability 2.5 Resilient Modulus 8,432 psi Design ESALs 730,000 Layers Structural Coefficient Drainage Thickness SN HMA 0.44 1 7.5 3.30 ABC 0.11 1.05 11.5 1.33 CSS 0.1 1 0 0.00 SUM 4.63 HARTFORD HOMES BLOOM FILING 1 ROADS, PHASE 3 CTL|T PROJECT NO. FC07733.010-135 Design Structural Number 3.07 International Boulevard Two-Lane Arterial Flexible Structural Design FIGURE B-2 APPENDIX C PAVEMENT CONSTRUCTION RECOMMENDATIONS HARTFORD HOMES BLOOM FILING 1 ROADS - PHASE 3 CTL  T PROJECT NO. FC07733.010-135 C-1 SUBGRADE PREPARATION Moisture Treated Subgrade (MTS) 1. The subgrade should be stripped of organic matter, scarified, moisture treated and compacted to the specifications stated below in Item 2. The compacted subgrade should extend at least 3 feet beyond the edge of the pavement where no edge support, such as curb and gutter, are to be constructed. 2. Sandy and gravelly soils (A-1-a, A-1-b, A-3, A-2-4, A-2-5, A-2-6, A-2-7) should be moisture conditioned near optimum moisture content and compacted to at least 95 percent of standard Proctor maximum dry density (ASTM D 698, AASHTO T 99). Clayey soils (A-6, A-7-5, A-7-6) should be moisture conditioned between optimum and 3 percent above optimum moisture content and compacted to at least 95 percent of standard Proctor maximum dry density (ASTM D 698, AASHTO T 99). 3. Utility trenches and all subsequently placed fill should be properly compacted and tested prior to paving. As a minimum, fill should be compacted to 95 percent of standard Proctor maximum dry density. 4. Final grading of the subgrade should be carefully controlled so the design cross- slope is maintained and low spots in the subgrade that could trap water are eliminated. 5. Once final subgrade elevation has been compacted and tested to compliance and shaped to the required cross-section, the area should be proof-rolled using a minimum axle load of 18 kips per axle. The proof-roll should be performed while moisture contents of the subgrade are still within the recommended limits. Drying of the subgrade prior to proof-roll or paving should be avoided. 6. Areas that are observed by the Engineer that have soft spots in the subgrade, or where deflection is not uniform of soft or wet subgrade shall be ripped, scarified, dried, or wetted as necessary and recompacted to the requirements for the density and moisture. As an alternative, those areas may be over-excavated and replaced with properly compacted structural backfill. Where extensively soft, yielding subgrade is encountered; we recommend a representative of our office observe the excavation. Chemically Stabilized Subgrade (CSS) 1. Utility trenches and all subsequently placed fill should be properly compacted and tested prior to subgrade preparation. As a minimum, fill should be compacted to 95 percent of standard Proctor maximum dry density. 2. The subgrade should be stripped of organic matter and should be shaped to final line and grade. HARTFORD HOMES BLOOM FILING 1 ROADS - PHASE 3 CTL  T PROJECT NO. FC07733.010-135 C-2 3. The contractor or owner’s representative can, if directed, have a mix design performed in general accordance with ASTM D 558 using the actual site soils and the approved stabilizing agent (lime, fly ash or a combination of lime and fly ash). Scheduling should allow at least eight weeks for the mix design to be completed prior to construction. 4. High calcium quicklime should conform to the requirements of ASTM C 977 and ASTM C 110. Dolomitic quicklime, magnesia quicklime with magnesium oxide contents in excess of 4 percent, or carbonated quicklime should not be used. 5. Fly ash should consist of Class C in accordance with ASTM C 593 and C 618. 6. All stabilizing agents should come from the same source as used in the mix design. If the source is changed, a new mix design should be performed. 7. Stabilizing agents should be spread with a mechanical spreader from back of curb to back of curb for detached sidewalks or back of walk to back of walk for attached sidewalks, where applicable. 8. The subgrade should be mixed to the specified depth and at the specified concentration until a uniform blend of soil, stabilizing agent and water is obtained and the moisture content is at least 2 percent (for cement and fly ash) and 3 percent (for lime) above the optimum moisture content of the design mixture (ASTM D 558). 9. If lime is used, a mellowing period of up to seven days may be required following initial mixing. Once the pH of the mixture is 12.3 or higher and the plasticity index is less than 10, the soils shall again be mixed and moisture conditioned to at least 3 percent over optimum moisture content and compacted to at least 95 percent of the mixture’s maximum dry density (ASTM D 558). Up to seven additional days may be required for curing prior to paving. The treated surface shall be kept moist or sealed with emulsified asphalt. Traffic should not be allowed on the surface during the mellowing and curing periods. 10. If fly ash is used, the mixture should be moisture conditioned to at least 2 percent over optimum moisture content and compacted to at least 95 percent of the mixture’s maximum dry density (ASTM D 558) within 2 hours from the time of initial fly ash mixing. 11. If a lime/fly ash combination is used, the lime should be mixed first and allowed to mellow as indicated for lime treatment in item 9. Following the mellowing period, the fly ash should be added, moisture conditioned and compacted as indicated above within 2 hours of initial fly ash mixing. 12. Samples of loose, blended stabilizing agent/soil mixture should be sampled by a representative of CTL Thompson, Inc. for compressive strength testing (ASTM D 1663) to determine compliance (optional) when full credit for the FASS layer is used in the pavement thickness design. 13. Batch tickets should be supplied to the owner or owner’s representative with the application area for that batch to determine compliance with the recommended proportions of fly ash to soil. HARTFORD HOMES BLOOM FILING 1 ROADS - PHASE 3 CTL  T PROJECT NO. FC07733.010-135 C-3 14. The subgrade should be re-shaped to final line and grade. 15. The subgrade should be sealed with a pneumatic-tire roller that is sufficiently light in weight so as to not cause hairline cracking of the subgrade. 16. Where sulfate concentrations are over 0.5 percent, a double treatment method should be performed. When a double treatment is required, the first half of the stabilizing agent should be placed, moisture treated and allowed to mellow or cure for at least two weeks. The remaining half of the stabilizing agent plus an additional 0.5 (for lime) to 2 (for fly ash) percent shall then be applied. 17. Mixing of the fly ash, lime, or lime/fly ash treated subgrade should not occur if the temperature of the soil mixture is below 40oF. 18. We recommend a minimum of 2 days curing prior to paving. The surface of the stabilized area should be kept moist during the cure period by periodic, light sprinkling if needed. Strength gains will be slower during cooler weather. Traffic should not be permitted on the treated subgrade during the curing period. The subgrade should be protected from freezing or drying at all times until paving. 19. Placement, mixing and compaction of stabilized subgrade should be observed and tested by a representative of our firm. Aggregate Base Course (ABC) 1. A Class 5 or 6 Colorado Department of Transportation (CDOT) specified ABC should be used. Reclaimed asphalt pavement (RAP) or reclaimed concrete pavement (RCP) alternative which meets the Class 5 or 6 designation and design R-value/strength coefficient is also acceptable. 2. Bases should have a minimum Hveem stabilometer value of 78, or greater. ABC, RAP, and RCP must be moisture stable. The change in R-value from 300-psi to 100-psi exudation pressure should be 12 points or less. 3. ABC, RAP, or RCP bases should be placed in thin lifts not to exceed 6 inches and moisture treated to near optimum moisture content. Bases should be moisture treated to near optimum moisture content and compacted to at least 95 percent of standard Proctor maximum dry density (ASTM D 698, AASHTO T 99). 4. Placement and compaction of ABC, RAP, or RCP should be observed and tested by a representative of our firm. Placement should not commence until the underlying subgrade is properly prepared and tested. HARTFORD HOMES BLOOM FILING 1 ROADS - PHASE 3 CTL  T PROJECT NO. FC07733.010-135 C-4 Hot Mix Asphalt (HMA) 1. HMA should be composed of a mixture of aggregate, filler, hydrated lime, and asphalt cement. Some mixes may require polymer modified asphalt cement, or make use of up to 20 percent reclaimed asphalt pavement (RAP). A job mix design is recommended and periodic checks on the job site should be made to verify compliance with specifications. 2. HMA should be relatively impermeable to moisture and should be designed with crushed aggregates that have a minimum of 80 percent of the aggregate retained on the No. 4 sieve with two mechanically fractured faces. 3. Gradations that approach the maximum density line (within 5 percent between the No. 4 and 50 sieves) should be avoided. A gradation with a nominal maximum size of 1 or 2 inches developed on the fine side of the maximum density line should be used. 4. Total void content, voids in the mineral aggregate (VMA) and voids filled should be considered in the selection of the optimum asphalt cement content. The optimum asphalt content should be selected at a total air void content of approximately 4 percent. The mixture should have a minimum VMA of 14 percent and between 65 percent and 80 percent of voids filled. 5. Asphalt cement should meet the requirements of the Superpave Performance Graded (PG) Binders. The minimum performing asphalt cement should conform to the requirements of the governing agency. 6. Hydrated lime should be added at the rate of 1 percent by dry weight of the aggregate and should be included in the amount passing the No. 200 sieve. Hydrated lime for aggregate pretreatment should conform to the requirements of ASTM C 207, Type N. 7. Paving should be performed on properly prepared, unfrozen surfaces that are free of water, snow, and ice. Paving should only be performed when both air and surface temperatures equal, or exceed, the temperatures specified in Table 401- 3 of the 2021 Colorado Department of Transportation Standard Specifications for Road and Bridge Construction. 8. HMA should not be placed at a temperature lower than 245oF for mixes containing PG 64-22 asphalt, and 290oF for mixes containing polymer-modified asphalt. The breakdown compaction should be completed before the HMA temperature drops 20oF. 9. Wearing surface course shall be Grading S or SX for residential roadway classifications and Grading S for collector, arterial, industrial, and commercial roadway classifications. 10. The minimum/maximum lift thicknesses for Grade SX shall be 1½ inches/2½ inches. The minimum/maximum lift thicknesses for Grade S shall be 2 inches/3½ inches. The minimum/maximum lift thicknesses for Grade SG shall be 3 inches/5 inches. HARTFORD HOMES BLOOM FILING 1 ROADS - PHASE 3 CTL  T PROJECT NO. FC07733.010-135 C-5 11. Joints should be staggered. No joints should be placed within wheel paths. 12. HMA should be compacted to between 92 and 96 percent of Maximum Theoretical Density. The surface shall be sealed with a finish roller prior to the mix cooling to 185oF. 13. Placement and compaction of HMA should be observed and tested by a representative of our firm. Placement should not commence until approval of the proof rolling as discussed in the Subgrade Preparation section of this report. Sub-base, base course or initial pavement course shall be placed within 48 hours of approval of the proof rolling. If the Contractor fails to place the sub-base, base course or initial pavement course within 48 hours or the condition of the subgrade changes due to weather or other conditions, proof rolling and correction shall be performed again. Portland Cement Concrete (PCC) 1. Portland cement concrete should consist of Class P of the 2021 CDOT - Standard Specifications for Road and Bridge Construction specifications for normal placement. PCC should have a minimum compressive strength of 4,500 psi at 28 days and a minimum modulus of rupture (flexural strength) of 600 psi. Job mix designs are recommended and periodic checks on the job site should be made to verify compliance with specifications. 2. Portland cement should be Type II “low alkali” and should conform to ASTM C 150. 3. Portland cement concrete should not be placed when the subgrade or air temperature is below 40°F. 4. Concrete should not be placed during warm weather if the mixed concrete has a temperature of 90°F, or higher. 5. Mixed concrete temperature placed during cold weather should have a temperature between 50°F and 90°F. 6. Free water should not be finished into the concrete surface. Atomizing nozzle pressure sprayers for applying finishing compounds are recommended whenever the concrete surface becomes difficult to finish. 7. Curing of the Portland cement concrete should be accomplished by the use of a curing compound. The curing compound should be applied in accordance with manufacturer recommendations. 8. Curing procedures should be implemented, as necessary, to protect the pavement against moisture loss, rapid temperature change, freezing, and mechanical injury. HARTFORD HOMES BLOOM FILING 1 ROADS - PHASE 3 CTL  T PROJECT NO. FC07733.010-135 C-6 9. Construction joints, including longitudinal joints and transverse joints, should be formed during construction, or sawed after the concrete has begun to set, but prior to uncontrolled cracking. 10. All joints should be properly sealed using a rod back-up and approved epoxy sealant. 11. Traffic should not be allowed on the pavement until it has properly cured and achieved at least 80 percent of the design strength, with saw joints already cut. 12. Placement of Portland cement concrete should be observed and tested by a representative of our firm. Placement should not commence until the subgrade is properly prepared and tested. APPENDIX D MAINTENANCE PROGRAM HARTFORD HOMES BLOOM FILING 1 ROADS - PHASE 3 CTL  T PROJECT NO. FC07733.010-135 D-1 MAINTENANCE RECOMMENDATIONS FOR FLEXIBLE PAVEMENTS A primary cause for deterioration of pavements is oxidative aging resulting in brittle pavements. Tire loads from traffic are necessary to "work" or knead the asphalt concrete to keep it flexible and rejuvenated. Preventive maintenance treatments will typically preserve the original or existing pavement by providing a protective seal or rejuvenating the asphalt binder to extend pavement life. 1. Annual Preventive Maintenance a. Visual pavement evaluations should be performed each spring or fall. b. Reports documenting the progress of distress should be kept current to provide information on effective times to apply preventive maintenance treatments. c. Crack sealing should be performed annually as new cracks appear. 2. 3 to 5 Year Preventive Maintenance a. The owner should budget for a preventive treatment at approximate intervals of 3 to 5 years to reduce oxidative embrittlement problems. b. Typical preventive maintenance treatments include chip seals, fog seals, slurry seals and crack sealing. 3. 5 to 10 Year Corrective Maintenance a. Corrective maintenance may be necessary, as dictated by the pavement condition, to correct rutting, cracking, and structurally failed areas. b. Corrective maintenance may include full depth patching, milling and overlays. c. In order for the pavement to provide a 20-year service life, at least one major corrective overlay should be expected. HARTFORD HOMES BLOOM FILING 1 ROADS - PHASE 3 CTL  T PROJECT NO. FC07733.010-135 D-2 MAINTENANCE RECOMMENDATIONS FOR RIGID PAVEMENTS High traffic volumes create pavement rutting and smooth, polished surfaces. Preventive maintenance treatments will typically preserve the original or existing pavement by providing a protective seal and improving skid resistance through a new wearing course. 1. Annual Preventive Maintenance a. Visual pavement evaluations should be performed each spring or fall. b. Reports documenting the progress of distress should be kept current to provide information of effective times to apply preventive maintenance. c. Crack sealing should be performed annually as new cracks appear. 2. 4 to 8 Year Preventive Maintenance a. The owner should budget for a preventive treatment at approximate intervals of 4 to 8 years to reduce joint deterioration. b. Typical preventive maintenance for rigid pavements includes patching, crack sealing and joint cleaning and sealing. c. Where joint sealants are missing or distressed, resealing is mandatory. 3. 15 to 20 Year Corrective Maintenance a. Corrective maintenance for rigid pavements includes patching and slab replacement to correct subgrade failures, edge damage and material failure. b. Asphalt concrete overlays may be required at 15-to-20-year intervals to improve the structural capacity of the pavement.