APPENDIX B RUNWAY PAVEMENT STRENGTHENING STUDY

Transcription

1 APPENDIX B RUNWA PAVEMENT STRENGTHENING STUD Prepared by: Hollaway Consulting Engineers, LLC November 2016 B-1

2 PROJECT BACKGROUND This report presents the details of the pavement strengthening analysis prepared as part of the Master Plan Update for the Conroe North Houston Regional Airport (CXO) in Conroe, Texas. CXO is expanding and growing rapidly. Construction of the Runway extension to 7,501 feet was completed in May Galaxy FBO recently broke ground on new hangar facilities, an expansion which will nearly double their hangar capacity. The Federal Inspection Service (FIS) was completed and opened in September Construction on the extension of Taxiway A will begin in the Fall of CXO anticipates future opportunities for scheduled commercial service and/or relocation of Federal agencies to the airport. Preplanning for this possibility includes finding a logical site for the facilities, as well as planning to strengthen the existing airfield pavement they will use to ensure the pavements are structurally sufficient to carry the additional weight of the larger aircraft. Designed and rated for 100,000 Dual Wheel (DW) aircraft, the existing airfield pavements will not accommodate 175,000 DW aircraft. Therefore, existing airfield pavement used by the larger aircraft will have to be strengthened or reconstructed. Presented below are the results of the study including four (4) pavementstrengthening methods, five (5) alternative locations for the facility, and anticipated construction and engineering budgets for each. Existing Airfield Pavements Runway is CXO s primary and longest runway. The Runway extension (from Runway 1-19 to the new Rwy 14 end) and Taxiway A were both constructed and opened to aircraft traffic in the Spring of The remainder of Runway 14-32, from Runway 1-19 to the Runway 32 end was reconstructed in approximately The extension of Taxiway A, scheduled for construction in the Fall of 2017, will turn Taxiway A into a full parallel taxiway to Runway Runway 14-32, Taxiway A and the extension of Taxiway A are each designed for 100,000 Dual Wheel (DW) Aircraft. They are constructed with a basic pavement section that includes 12-inches of Lime Stabilized Subgrade, eight (8) inches of Cement Treated Base and 12-inches of Reinforced Portland Cement Concrete. All pavement designs were completed using the design program FAARFIELD, required by the Federal Aviation Administration (FAA), and constructed in accordance with FAA Advisory Circular (AC) construction standards. Because Runway is the airport s primary runway, the airport s longest runway, will have a full parallel taxiway, and has a CATI Instrument Landing System (ILS), it is the only runway analyzed for use by heavy aircraft in this pavement strengthening study. The full parallel Taxiway A was also analyzed because it will be used by heavy aircraft access to the runway. Alternative Pavement Strengthening Methods Four (4) alternative pavement-strengthening methods were considered for this study including three (3) Portland Cement Concrete (PCC) and one (1) Hot Mix Asphaltic Concrete (HMAC). Alternatives included Bonded Overlays, Partially Bonded Overlays, Unbonded Overlays and HMAC Overlay. Reconstruction of the pavements was not considered because the majority of the existing airfield pavements have been recently reconstructed or are planned for reconstruction in the near future. Additionally, reconstruction is the most expensive option and would likely be cost prohibitive. Bonded overlays become part of the underlying existing pavement they work together. They are 2 to 5 inches thick and typically applied to strengthen an existing pavement, or for B-2

3 preventive maintenance. Bonded overlays should not be used if the existing pavement is in poor condition. Bonded overlays must be bonded to the existing pavement since the load-carrying capacity of the pavement is relying on the strength of the existing pavement. This means good surface preparation is necessary and critical to the successful completion. Damage to or cracking of existing pavement panels must be repaired; joints must be in good condition and working as designed. Joints (and any cracks) in the overlay must match up exactly with the joints in the existing pavement; otherwise the joint or crack will reflect through the overlay. Prior to placing the overlay, the existing pavement must be milled or shot blasted to ensure and enhance the bond. Grout or special adhesives can be applied to the existing surface prior to paving to enhance the bond. Ultimately, the old pavement and the overlay move as one unit, so the thermal expansion properties of the two materials have to match. For these reasons, bonded overlay projects are more challenging. However, they are typically thinner, use less material, hence are usually less expensive. There are advantages to using a bonded overlay. Since the old pavement and overlay are designed to work together, much thinner sections of concrete can be used, lowering anticipated construction costs. Thinner overlay sections mean it is easier to slope the runway and taxiway shoulders to meet the existing airfield lighting, minimizing if not eliminating the requirement to adjust all of the MIRLs, MITLs and threshold lights. There is also less chance of an impact to the existing published runway approaches due to changes in the runway end elevation. (The FAA typically allows up to 12 in elevation change of a runway end elevation before requiring new approaches). Conversely, bonded overlays can only be used on sound, distress free pavements. The overlay must be matched exactly to the existing pavement jointed concrete pavement must be placed on jointed concrete pavement. The overlay joints must exactly match the underlying joints of the existing pavement, both in location and type of joint. All pavement distresses and cracks must be repaired and the joints must be sound and in good condition. Surface preparation prior to the overlay is critical to achieve a full bond and a full bond is required for the pavement strength. Timing of the initial sawcutting on the joints is critical to prevent cracking and delamination (de-bonding) of the overlay. Bonded overlays recently completed on Texas airports have not been particularly successful and some ultimately resulted in demolition and full reconstruction of the newly overlaid pavements. Therefore, bonded overlays are not included in this evaluation. Unbonded overlays, typically 4 to 11 inches thick depending on the desired life span and anticipated traffic, are a pavement structure on their own the existing pavement is only used as a supporting base. This means unbonded overlays are thicker than a bonded overlay, but are the only choice if the pavement is in less than good condition. They are essentially a new pavement, so the strength of the existing pavement is not relied upon to carry the load. An unbonded overlay on an existing concrete pavement must be completely unbonded. This is typically accomplished by paving 1.5 to 2 inches of asphalt with a membrane curing compound between the existing pavement and the overlay. With a few special considerations, the resurfacing is constructed as if the underlying pavement were a conventional subbase layer. Fully unbonded PCC overlays behave eventually as slabs supported by a firm subgrade. However, due to the very stiff nature of the existing pavement, thermal curling stresses in unbonded pavement can cause cracks if the joints are not closely spaced. Following are the advantages and disadvantages of the unbonded type of overlays. B-3

4 Advantages: It is not necessary to match the joints between the existing pavements and overlays. It is not necessary to clean or seal joints in the existing pavements. Surface preparation is not as critical. No special construction techniques are needed for construction. Disadvantages: The greater pavement thickness is more expensive. Increased construction costs associated with longer pavement transitions at airfield pavement intersections. Approaches may change due to changes in the runway end elevations. Elevation differentials can result in changes to the airfield lighting. The thickness of the overlay may not be economically feasible for most projects. Structural distresses cannot be ignored and must be repaired to ensure uniform support. CXO may be a good candidate for an unbonded overlay dependent on when the proposed pavement strengthening project is completed. Currently, most of the affected pavements, Runway and Taxiway A, are new and in good condition. The remainder of Taxiway A will be constructed in 2017, completing a full parallel for Runway However, if the pavement strengthening is not completed for five or even 10 years or more, there will be deterioration of the existing pavements, even if they are expertly maintained. Deterioration of the pavements can result in requirements for a thicker overlay and the need to complete structural repairs to any pavement panels that have cracked and become structurally unsound. However, even a well-maintained pavement that is 10 or 15 years old will continue to have value as a quality base for the new unbonded overlay. Partially bonded overlays are used when bonding between the overlay and underlying pavement is of little importance, such as on thick airfield pavement. Partially bonded overlays can be placed without milling or shot blasting the existing pavement surfaces and without grout or special additives typically required to promote bonding. Surface preparation is not required for a partially bonded overlay. The only requirements for partially bonded overlays are that the surface be free of loose materials and that the existing concrete surface be sound. Because no particular attention is paid to cleaning or grinding the base pavement, various degrees of bonding may occur. However, this has minimal bearing on the performance of the resurfacing. Recent literature considers partially bonded overlays to be special cases of the unbonded type of overlay, because the evidence shows that the performance is similar. Partially bonded overlays should only be used on reasonably sound existing pavements, since most cracks in the existing slab will reflect through the overlay within a short period. Maintenance of the existing pavement is very important when completing a partially bonded overlay. The existing pavement has to be structurally sound, including all of the joints, for the partially bonded overlay to perform over the 20-year design life. Ideally, the minimum thickness for partially bonded overlays is six (6) inches, although five (5) inch overlays have been used successfully. Unless joints are closely spaced, however, significant cracking between joints is expected when thin partially bonded overlays are used. B-4

5 HMAC overlay on the existing concrete pavement is another option for strengthening the airfield pavements. HMAC is designed on airfield pavement primarily as a riding surface, with the structural strength coming from the underlying pavement structure. The most challenging issue for HMAC overlays over concrete pavements is the development of reflection cracks through the overlays at the locations of joints and existing cracks on concrete pavements. There are some techniques available to minimize this reflection or mirror cracking in the HMAC, however, most have been ineffective over time. All pavement designs were completed in accordance with FAA Advisory Circulars and using FAARFIELD, the FAA s pavement design program. They were based on the aircraft mix developed as part of this Master Plan. Existing Record Drawings for Runway extension project were used, along with the proposed plans for Taxiway A parallel taxiway extension project. New pavement design for access taxiways and aprons for the proposed facility were developed using existing geotechnical information from the Runway extension project. While the designs were developed using readily available information, they are not intended to be used for final design and construction. They were developed solely to prepare the budget estimates provided in this report. Detailed geotechnical investigations of the selected site, as well as detailed pavement investigations, including pavement coring, Pavement Condition Investigations and Falling Weight Deflectometer analysis, should be completed by the engineer to develop detailed construction plans for the proposed strengthening project. Preliminary Results of the pavement design and anticipated pavement section are presented in Figures 1 through 4 below. The unbonded overlay, presented in Figure 1, will require 12 inches of concrete overlay on the existing pavements. The partially bonded overlay, presented in Figure 2, will require six (6) inches of concrete overlay on the existing pavements. The HMAC Overlay, presented in Figure 3, will require six (6) inches of overlay on the existing pavements. All new pavement, presented in Figure 4, will require 12 inches of lime fly-ash stabilized subgrade, eight (8) inches of cement treated base and 13 inches of new PCC pavement. B-5

6 Figure 1 PCC UNBONDED OVERLA AIRFIELD PAVEMENT STRENGTHENING PROJECT CONROE NORTH HOUSTON REGIONAL AIRPORT CONROE,TEXAS FAARFIELD - Airport Pavement Design (V 1.305, 9/28/10 64-bit) Section PCConRigid01 in Job CXO01. Working directory is C:\Program Files (x86)\faa\faarfield\ The structure is Unbonded PCC Overlay on Rigid. SCI of the existing pavement = 40. Design Life = 20 years. A design for this section was completed on 10/30/16 at 19:32:07. Pavement Structure Information by Layer, Top First No. Type Thickness Modulus Poissons Strength in psi Ratio R,psi 1 PCC Overlay Unbond ,000, PCC Surface ,000, P-304 CTB , Undefined , Subgrade , Total thickness to the top of the subgrade = in Figure 2 PCC PARTIALL BONDED OVERLA AIRFIELD PAVEMENT STRENGTHENING PROJECT CONROE NORTH HOUSTON REGIONAL AIRPORT CONROE,TEXAS FAARFIELD - Airport Pavement Design (V 1.305, 9/28/10 64-bit) Section PCConRigid02 in Job CXO01. Working directory is C:\Program Files (x86)\faa\faarfield\ The structure is Part Bonded PCC Overlay on Rigid. SCI of the existing pavement = 77. Design Life = 20 years. A design for this section was completed on 10/31/16 at 12:50:51. Pavement Structure Information by Layer, Top First No. Type Thickness Modulus Poissons Strength in psi Ratio R,psi 1 PCC Overlay Part Bond ,000, PCC Surface ,000, P-304 CTB , Undefined , Subgrade , Total thickness to the top of the subgrade = in B-6

7 Figure 3 HOT MIX ASPHALTIC CONCRETE (HMAC) OVERLA AIRFIELD PAVEMENT STRENGTHENING PROJECT CONROE NORTH HOUSTON REGIONAL AIRPORT CONROE,TEXAS FAARFIELD - Airport Pavement Design (V 1.305, 9/28/10 64-bit) Section AConRigid01 in Job CXO01. Working directory is C:\Program Files (x86)\faa\faarfield\ The structure is AC Overlay on Rigid. SCI of the existing pavement = 90. Design Life = 20 years. A design for this section was completed on 10/31/16 at 15:08:48. Pavement Structure Information by Layer, Top First No. Type Thickness Modulus Poissons Strength in psi Ratio R,psi 1 P-401/ P-403 HMA Overlay , PCC Surface ,000, P-304 CTB , Undefined , Subgrade , Total thickness to the top of the subgrade = in Figure 4 NEW PCC PAVEMENTS AIRFIELD PAVEMENT STRENGTHENING PROJECT CONROE NORTH HOUSTON REGIONAL AIRPORT CONROE,TEXAS FAARFIELD - Airport Pavement Design (V 1.305, 9/28/10 64-bit) Section NewRigid01 in Job CXO01. Working directory is C:\Program Files (x86)\faa\faarfield\ The structure is New Rigid. Design Life = 20 years. A design for this section was completed on 10/31/16 at 13:44:48. Pavement Structure Information by Layer, Top First No. Type Thickness Modulus Poissons Strength in psi Ratio R,psi 1 PCC Surface ,000, P-304 CTB , Undefined , Subgrade , Total thickness to the top of the subgrade = in B-7

8 ALTERNATIVE LOCATIONS AND BUDGETS Five alternative locations for the proposed commercial service terminal or Federal hangar facility were developed for this study. These Alternatives are shown in Exhibits 1 through 5 and are attached. Runway is the only runway considered for use by heavier aircraft. Detailed Preliminary Engineer s Opinion of Probable Construction Cost Estimates for design and construction of each alternative for each overlay type are presented in Tables 1 through 9. Alternative 1 For Alternative 1, as shown in Exhibit 1, the new facility was sited south and east of the intersection of Runway 1-19 and Taxiway F. Aircraft will taxi along Taxiway F to access Taxiway A and Runway The full length of Runway and Taxiway A will be strengthened with an overlay. The entrance Taxiway G will be strengthened between Taxiway F and Runway Intermediate cross taxiways along the runway and parallel taxiway were not strengthened. However, these intersections will require approximately 75 of transition pavement on either side of an intersection to account for the difference in elevation due to the strengthening overlay on the Runway and Taxiway A. Transition pavement should be sloped at a 1% grade as required by FAA AC s. The preliminary construction and engineering costs were developed based on the following assumptions: Construction of full parallel Taxiway A will be complete prior to pavement strengthening MIRLs and MITLs (Medium Intensity Runway (Taxiway) Lights) fixtures can be replaced with new fixtures on 24 adjustable stems for adjusting to the new grade. Reconstruction of Taxiway F will be complete prior to reconstruction Taxiway F pavement will be designed and reconstructed for 175,000 DW aircraft, eliminating the need for a full overlay on Taxiway F. Taxiway F MITLs will be installed with 24 adjustable lights. All apron and access taxiways for the new facility will be constructed with the pavement strengthening project. New construction will include hangar and access taxilane pavement to Taxiway F. The estimated construction costs for Alternative 1 are as follows: Unbonded Overlay $32,363,400 Partially Bonded Overlay $25,105,800 HMAC Overlay $16,798,600 Alternative 2A and 2B For Alternative 2A and 2B, as shown in Exhibits 2 and 3, the new facility was sited north and east of the intersection of Runway and Taxiway G. A new parallel taxiway will be constructed on the northern side of Runway With these two alternatives, the new parallel taxiway will require the installation of large box culverts to cross the drainage ditch leading into the detention pond. Based on the recent Runway extension project, this work could potentially cost more than $1.3 million. Additionally, due to FAA requirements for runway to parallel taxiway separation, the proposed parallel taxiway will require relocation of the Glide B-8

9 NO. DATE N LEGEND: PROPOSED RUNWA AND TAXIWA STRENGTHENING OVERLA PROPOSED NEW TAXIWA PAVEMENT REVISION 0 GENERAL NOTES: G K A B A H F A J RUNWA A NW RU A C PROP FEDERAL MARSHAL BUILDING (ALTERNATIVE 1) TBPE FIRM #16784 D THIS DOCUMENT IS RELEASED FOR THE PURPOSE OF REVIEW ONL UNDER THE AUTHORIT OF SHERI E. HOLLAWA, P.E ON 10/10/2016. IT SHALL NOT BE USED FOR CONSTRUCTION, BIDDING, RECORDATION, CONVEANCE, SALES, OR AS THE BASIS FOR ISSUANCE OF A PERMIT. DATE: NOVEMBER 2016 PROJECT TITLE: CONROE-NORTH HOUSTON REGIONAL AIRPORT PAVEMENT ALTERNATIVES FOR FEDERAL MARSHAL SERVICE DRAWING TITLE: ALTERNATIVE 1 DRAWING NUMBER: EXHIBIT 1 SCALE: B-9 DRAWN B: F 1:400 H 1:800 CHECKED B:

10 NO. DATE N LEGEND: PROPOSED RUNWA AND TAXIWA STRENGTHENING OVERLA PROPOSED NEW TAXIWA PAVEMENT REVISION 0 PROP FEDERAL MARSHAL BUILDING (ALTERNATIVE 2A) GENERAL NOTES: G K B A H F J RUNWA A NW RU A C TBPE FIRM #16784 THIS DOCUMENT IS RELEASED FOR THE PURPOSE OF REVIEW ONL UNDER THE AUTHORIT OF SHERI E. HOLLAWA, P.E ON 10/10/2016. IT SHALL NOT BE USED FOR CONSTRUCTION, BIDDING, RECORDATION, CONVEANCE, SALES, OR AS THE BASIS FOR ISSUANCE OF A PERMIT. D DATE: NOVEMBER 2016 PROJECT TITLE: CONROE-NORTH HOUSTON REGIONAL AIRPORT PAVEMENT ALTERNATIVES FOR FEDERAL MARSHAL SERVICE DRAWING TITLE: ALTERNATIVE 2A DRAWING NUMBER: EXHIBIT 2 B-10 SCALE: DRAWN B: F 1:400 H 1:800 CHECKED B:

11 NO. DATE N LEGEND: PROPOSED RUNWA AND TAXIWA STRENGTHENING OVERLA PROPOSED NEW TAXIWA PAVEMENT REVISION 0 PROP FEDERAL MARSHAL BUILDING (ALTERNATIVE 2B) GENERAL NOTES: G K B A H F J RUNWA A NW RU A C TBPE FIRM #16784 D THIS DOCUMENT IS RELEASED FOR THE PURPOSE OF REVIEW ONL UNDER THE AUTHORIT OF SHERI E. HOLLAWA, P.E ON 10/10/2016. IT SHALL NOT BE USED FOR CONSTRUCTION, BIDDING, RECORDATION, CONVEANCE, SALES, OR AS THE BASIS FOR ISSUANCE OF A PERMIT. DATE: NOVEMBER 2016 PROJECT TITLE: CONROE-NORTH HOUSTON REGIONAL AIRPORT PAVEMENT ALTERNATIVES FOR FEDERAL MARSHAL SERVICE DRAWING TITLE: ALTERNATIVE 2B DRAWING NUMBER: EXHIBIT 3 -SCALE: B-11 DRAWN B: F 1:400 H 1:800 CHECKED B:

12 Slope Antenna, Shack and Automated Surface and Observation System (ASOS) (weather reporting station). Also, based on the recent runway project, this relocation could potentially cost more than $200,000 as well as require additional time and costs to coordinate a new site for the Glide Slope Antenna and shack that is acceptable to the FAA and meets their siting requirements. Finally, construction of the new parallel taxiway is estimated to cost approximately $6.7 Million additional dollars. It should be noted that Alternative 2A and 2B are virtually the same project, with the location of the facility flipped either north or south on the runway end. Detailed investigations during design may indicate one site or the other as preferred due to existing topography, site soils or other factors. However, for the purpose of this preliminary study, the two sites are indistinguishable. The estimated construction budgets are therefore the same. The estimated construction costs for Alternative 2A and 2B are as follows: Unbonded Overlay $43,325,500 Partially Bonded Overlay $37,024,200 HMAC Overlay $34,445,200 Alternative 3A and 3B For Alternative 3A and 3B, as shown in Exhibits 4 and 5, the new facility was sited north and east of the intersection of Runway and Taxiway G. Aircraft will taxi south to Runway 32. They can also cross the Runway 32 to access Taxiway A, taxiing north along Taxiway A to reach Runway 14. For this alternative, the full length of Runway and Taxiway A will be strengthened. The entrance Taxiway G will be strengthened between Taxiway A and Runway Intermediate cross taxiways along the runway and parallel taxiway were not strengthened. However, these intersections will require transition pavement to account for the difference in elevation due to the strengthening overlay. New construction will include apron and access taxilane pavement to the Runway. The preliminary construction and engineering costs were developed based on the following assumptions: Construction of full parallel Taxiway A will be complete prior to pavement strengthening MIRLs and MITLs fixtures can be replaced with new fixtures on 24 adjustable stems All apron and access taxiways will be constructed with the pavement strengthening project. It should be noted that Alternative 3A and 3B are virtually the same project, with the location of the facility flipped either north or south on the runway end. Detailed investigations during design may indicate one site or the other as preferred due to existing topography, site soils or other factors. However, for the purpose of this preliminary study, the two sites are indistinguishable. The estimated construction budgets are therefore the same. B-12

13 The estimated construction costs for Alternative 3A and 3B are as follows: Unbonded Overlay $32,972,100 Partially Bonded Overlay $25,582,200 HMAC Overlay $16,788,000 SUMMAR It should be noted, that Alternative 1, 3A and 3B involve identical overlay costs, regardless of the type of overlay. The true differential in the developed construction budget is the location of the proposed site and associated construction costs for new apron and taxilane pavements. It is not possible to conclusively recommend one overlay method as preferred based on this preliminary analysis. Currently, CXO pavements included in this study are in excellent condition, and other pavements have yet to be constructed. The purpose of this study was to provide preliminary budget estimates. It should also be noted that construction of an HMAC overlay requires more maintenance in the long term. Crack Sealing, maintenance seal coats and even overlays are sometimes required to maintain the pavement in top condition for a 20- year life. A cost benefit analysis, not included in this scope of work, may show the long term, 20-year life of an HMAC overlay as more expensive than a partially unbonded concrete overlay. Any PCC overlay, whether a bonded overlay or partially bonded overlay, will require closing Runway and Taxiway A for the duration of the overlay. Overlay of the runway and parallel taxiway cannot be decoupled due to the grade difference created by the overlay. It is possible to shorten Runway while construction of the overlay of the runway northwest of Runway 1-19 is completed. However, once that portion of the runway is completed, it will be necessary to close the runway and taxiway for the duration of the construction. The Airport should anticipate that overlaying Runway and Taxiway A, with all of the cross taxiway transitions, will require 6-8 months. The thinner partially bonded overlay requiring roughly 6 months to complete and the thicker unbonded overlay requiring approximately 8 months to complete. Total construction time for the project, including new taxilane and apron, is anticipated to require approximately 1 year. The HMAC overlay presents many more options for construction phasing. Since the 6 overlay will likely be completed in 2 lifts, it is possible to phase the work so that the runway remains open by completing the work at night or during weekend runway closures. For night or weekend closures, the runway would be scheduled closed at a certain hour and scheduled to reopen at a certain hour. All construction activities scheduled for that night or weekend would be completed within that period. At the end of each evening or weekend of paving, the contractor would provide a temporary transition from the newly paved section to the existing runway surface. This has been successfully done at other commercial and GA airports in Texas, such as McAllen Miller International Airport and David W. Hooks Airport. To complete an overlay of the primary runway using only nights or weekend closures requires very extensive coordination and planning between the contractor, airport and construction administrator. The contractor is typically required to preplan the exact amount of work to be completed each evening or weekend. Backup equipment must be onsite so that the paving can continue even in the event of an equipment failure or breakdown. The contractor has to provide lighting for all night work. Issuance of Notices to Airmen (NOTAMs) is critical. Requiring a contractor to complete an overlay using only night or weekend work is more expensive. Night and weekend work, in lieu B-13

14 NO. DATE N LEGEND: PROPOSED RUNWA AND TAXIWA STRENGTHENING OVERLA PROPOSED NEW TAXIWA PAVEMENT REVISION 0 PROP FEDERAL MARSHAL BUILDING (ALTERNATIVE 3A) GENERAL NOTES: G K B A H F J RUNWA A NW RU A C TBPE FIRM #16784 D THIS DOCUMENT IS RELEASED FOR THE PURPOSE OF REVIEW ONL UNDER THE AUTHORIT OF SHERI E. HOLLAWA, P.E ON 10/10/2016. IT SHALL NOT BE USED FOR CONSTRUCTION, BIDDING, RECORDATION, CONVEANCE, SALES, OR AS THE BASIS FOR ISSUANCE OF A PERMIT. DATE: NOVEMBER 2016 PROJECT TITLE: CONROE-NORTH HOUSTON REGIONAL AIRPORT PAVEMENT ALTERNATIVES FOR FEDERAL MARSHAL SERVICE DRAWING TITLE: ALTERNATIVE 3A DRAWING NUMBER: EXHIBIT 4 SCALE: B-14 DRAWN B: F 1:400 H 1:800 CHECKED B:

15 NO. DATE N LEGEND: PROPOSED RUNWA AND TAXIWA STRENGTHENING OVERLA PROPOSED NEW TAXIWA PAVEMENT REVISION 0 PROP FEDERAL MARSHAL BUILDING (ALTERNATIVE 3B) GENERAL NOTES: G K B A H F J RUNWA A NW RU A C TBPE FIRM #16784 D THIS DOCUMENT IS RELEASED FOR THE PURPOSE OF REVIEW ONL UNDER THE AUTHORIT OF SHERI E. HOLLAWA, P.E ON 10/10/2016. IT SHALL NOT BE USED FOR CONSTRUCTION, BIDDING, RECORDATION, CONVEANCE, SALES, OR AS THE BASIS FOR ISSUANCE OF A PERMIT. DATE: NOVEMBER 2016 PROJECT TITLE: CONROE-NORTH HOUSTON REGIONAL AIRPORT PAVEMENT ALTERNATIVES FOR FEDERAL MARSHAL SERVICE DRAWING TITLE: ALTERNATIVE 3B DRAWING NUMBER: EXHIBIT 5 SCALE: B-15 DRAWN B: F 1:400 H 1:800 CHECKED B:

16 of full runway closure, was not included in the budget estimates. However, night and weekend closures will extend the construction time and increase the overall construction costs. However, under weekend work or night work phasing, the runway and taxiway would never be closed during CXO s busy week days. The total construction duration for the HMAC overlay is approximately 8 months. This analysis presents a snapshot in time of the anticipated construction and design costs for strengthening the airfield pavements at CXO for future use by heavier 175,000 DW aircraft. The studies are based on the current condition of the airfield pavements and their anticipated remaining life. The Preliminary Engineer s Opinion of Probable Construction Costs are intended to be used for Capital Improvement Planning and budgeting based on the current 2016 construction market in the Houston Metropolitan Area. It is recommended that CXO revisit the construction budgets on an annual or semi-annual basis to update the unit prices to reflect current construction cost trends. B-16